Brachycephalic Airway Syndrome

Brachycephalic Airway Syndrome – An Overview

Upper Airway Problems Seen in Short-Nosed Breeds

  • Partial upper airway obstruction in short-nosed, flat-faced (brachycephalic) breeds of dogs caused by any combination of the following conditions: narrowed nostrils (known as “stenotic nares”); overly long soft palate; turning inside-out of a portion of the voice box or larynx (known as “everted laryngeal saccules”), such that the space for air to pass through the larynx is decreased; and collapse of the voice box or larynx (known as “laryngeal collapse”)
  • An abnormally small windpipe or trachea (known as “hypoplastic trachea”) often is present as well, and can worsen breathing difficulty (respiratory distress)
  • “Upper respiratory tract” (also known as the “upper airways”) includes the nose, nasal passages, throat (pharynx), and windpipe (trachea)

Genetics

  • No specific genes have been identified
  • Short-nosed, flat-faced, broad (brachycephalic) head shape was initially an inherited defect in development of skull bones; has been perpetuated by selective breeding in certain breeds of dogs

Signalment/Description of Pet

Breed Predilections

  • Common syndrome in brachycephalic breeds of dogs

Mean Age and Range

  • Young adults, most diagnosed by 2–3 years of age
  • If diagnosed later than 4 years of age, another disease or condition may be adding to upper airway obstruction leading to diagnosis; older dogs may have a worse outcome post-operatively, but most have some improvement
  • Collapse of the voice box or larynx (known as “laryngeal collapse”) reported in short-nosed, flat faced (brachycephalic) breed puppies as young as 6–7 months of age

Signs/Observed Changes in Pet

  • Snoring; high-pitched, noisy breathing (stridor); noisy breathing when inhaling (stertorous breathing)
  • Rapid breathing (known as “tachypnea”), frequent panting
  • Coughing and gagging
  • Difficulty eating and swallowing
  • Excessive salivation (known as “ptyalism”), regurgitation (return of food or other contents from the esophagus or stomach back up through the mouth), and vomiting
  • Occasionally, fainting (syncope) and episodes of collapse
  • Narrowed nostrils (stenotic nares)
  • Increased breathing (respiratory) effort—may see pulling back of the lips with each breath, open-mouth breathing or constant panting, increased breathing rate, turning of the elbows away from the body (abduction of forelimbs) in an effort to open up the chest, increased abdominal effort during breathing
  • In severe breathing distress, may have increased difficulty in breathing while lying flat (known as “orthopnea”), even to point of reluctance to lie down; and bluish discoloration of skin and moist tissues of body (known as “cyanosis”)
  • Increased body temperature (known as “hyperthermia”) may be present

Causes

  • Brachycephalic airway syndrome results from inherited defects or developmental/growth defects of the upper airway. These defects include the following:
  • Elongated soft palate—reported in over 90% of surgical cases in dogs
  • Narrowed nostrils (stenotic nares)—reported in about 50% of cases in dogs
  • Voice box or laryngeal disease—everted laryngeal saccules (over 50% of affected dogs) and/or laryngeal collapse (approximately 10% of affected dogs)
  • Abnormally small windpipe (hypoplastic trachea); primarily in the English bulldog

Risk Factors

  • Brachycephalic breed
  • Obesity—worsens airway obstruction; associated with poorer outcome following surgical correction; may contribute to backward or reverse flow of stomach contents into the esophagus (known as “gastroesophageal reflux”) and development of aspiration pneumonia
  • Excitement and/or warm, humid weather—increased panting can lead to fluid buildup (edema) in the tissues of the airway, further narrowing the airway opening, and leading to increased body temperature (hyperthermia)
  • Exercise—dogs often are unable to exercise because of airway compromise and low levels of oxygen in their blood (hypoxia)
  • Sedation may cause relaxation of the muscles of throat (pharynx) and soft palate, and may cause complete airway obstruction
  • Lung disease (such as pneumonia, pulmonary edema)—will cause additional breathing compromise
  • Endocrine disease (such as low levels of thyroid [known as “hypothyroidism”] or high levels of steroids [known as “hyperadrenocorticism” or “Cushing’s syndrome”])—could worsen weight gain and cause excessive panting

Treatment

Health Care

  • Surgery recommended for pets with significant clinical signs
  • Emergency presentation with pet in severe breathing distress requires rapid medical intervention, including oxygen supplementation
  • If the pet has high body temperature (hyperthermia), cool with iced water and by directing a fan to blow over the pet (increase convective heat loss); intravenous (IV) fluids should be administered, up to a shock rate if has an extremely elevated body temperature (greater than 106°F)
  • If the airway is completely obstructed, the airway must be opened; this may be accomplished by passing an endotracheal tube through the mouth and into the windpipe (known as “orotracheal intubation”) and/or by a surgical incision into the windpipe (known as a “temporary tracheostomy”)
  • Dexamethasone can be administered to reduce inflammation
  • Pets need 24-hour monitoring because of risk of acute airway obstruction and death
  • Breathing rate and effort, heart rate, pulse quality, color of gums and moist tissues (mucous membrane color), time for pink color to return to gums after blanching them with one’s finger (capillary refill time), temperature, and other physical parameters should be monitored
  • Pulse oximetry and arterial blood gases to determine oxygen levels in the blood may be monitored, depending on severity of condition
  • Intravenous fluids are administered at maintenance rate and handling and stress are minimized

Activity

  • Usually self-limited by the pet

Diet

  • Weight loss is recommended for all overweight dogs
  • For obese, stable pets, weight loss is recommended prior to surgery

SURGERY

  • Evaluation for elongated soft palate generally is performed under general anesthesia when the pet is stable
  • Surgical incision into the windpipe (temporary tracheostomy) can be performed to facilitate exposure or to treat airway obstruction
  • Narrowed nostrils (stenotic nares) are corrected by surgically removing a wedge of the nasal tissue and closing the incision in such a manner to allow the nostril to be enlarged
  • Elongated soft palate is treated by surgically removing a section of the soft palate using surgical scissors, carbon dioxide laser, or a bipolar sealing device
  • Everted laryngeal saccules are treated by surgically trimming the tissue
  • Permanent surgical opening into the windpipe or trachea (known as a “permanent tracheotomy”) may be necessary if severe laryngeal collapse is present

Medications

Medications presented in this section are intended to provide general information about possible treatment. The treatment for a particular condition may evolve as medical advances are made; therefore, the medications should not be considered as all inclusive.

  • Dexamethasone to reduce fluid buildup (edema) and inflammation
  • Broad-spectrum antibiotics are indicated if aspiration pneumonia is present, until culture and sensitivity results are obtained
  • Omeprazole, cisapride, and magnesium hydroxide after meals or sucralfate resulted in improvement in dogs that also have inflammation of the esophagus (known as “esophagitis”), inflammation of the stomach (known as “gastritis”) and/or inflammation of the upper small intestine (known as the “duodenum”; condition known as “duodenitis”)

Follow-Up Care

Patient Monitoring

  • Post-operatively, 24-hour monitoring to observe for airway swelling and obstruction, which may require surgical incision into the windpipe (temporary tracheostomy)
  • Breathing rate, effort, heart rate, pulse quality, mucous membrane color, capillary refill time, temperature, and other physical parameters should be monitored

Preventions and Avoidance

  • Selection by breeders for dogs without severe conformational changes—may be difficult because breed standards encourage these structural changes
  • Avoid risk factors, particularly weight gain

Possible Complications

  • Overheating and heat stroke
  • Aspiration pneumonia (inflammation of the lungs, caused by accidentally inhaling food, vomit, or liquids into the airways)
  • Death in about 10% of affected pets as a result of airway disease
  • Most common post-operative complication is airway swelling and obstruction within the first 24 hours, may necessitate surgical incision into the windpipe (temporary tracheostomy)
  • Continued breathing difficulty after corrective surgery
  • Excessive shortening of the soft palate resulting in aspiration of food contents into the nasal cavity due to inability to close off the area between the nose and throat (known as the “nasopharynx”) during swallowing

Expected Course and Prognosis

  • Prognosis is good for improvement in breathing (80% of cases have good to excellent results following surgery) but airway is still far from normal
  • Prognosis better for dogs other than English bulldogs and for dogs that have correction of narrowed nostrils (stenotic nares) and elongated soft palate during same surgery
  • Without surgery, prognosis is poor due to continued progression of brachycephalic airway syndrome
  • Lifelong avoidance of risk factors recommended to decrease chance of developing clinical signs or worsening of disease

Key Points

  • Avoidance of risk factors is critical
  • Dogs with brachycephalic airway syndrome are at increased anesthetic risk, and an even higher risk occurs if they also have obesity, heart disease, or aspiration pneumonia (inflammation of the lungs, caused by accidentally inhaling food, vomit, or liquids into the airways)
  • Surgery often improves the clinical signs but does not result in a completely normal airway

Corneal and Scleral Lacerations

Corneal and Scleral Lacerations – An Overview

  • “Corneal” refers to the cornea; “scleral” refers to the sclera of the eye
  • The “cornea” is the clear outer layer of the front of the eye; the “sclera” is the white part of the eye, it is composed of a tough covering that protects the eyeball
  • “Penetrating” injury—a wound or foreign body that enters, but does not completely pass through the cornea or sclera; it also is known as a “non-perforating” injury
  • “Perforating” injury—a wound or foreign body that completely passes through the cornea or sclera; greater risk of vision loss than with penetrating injury
  • “Simple”—involves only the cornea or sclera; may be penetrating or perforating; other eye structures are intact (that is, not injured)
  • “Complicated”—a type of perforating injury; involves other eye structures in addition to the cornea or sclera; may involve the uvea (the entire middle layer of the eyeball that contains the blood vessels; it is composed of the iris [the colored or pigmented part of the eye], the ciliary body [the area between the iris and the choroid], and the choroid [located under the back part of the eye—the retina); the vitreous (the clear, gel-like material that fills the back part of the eyeball [between the lens and the retina]); or the retina (back part of the eye that contains the light-sensitive rods and cones and other cells that convert images into signals and send messages to the brain, to allow for vision); may also have trauma to the lens leading to cataracts or lacerations to the eyelids
  • The pupil is the circular or elliptical opening in the center of the iris of the eye; light passes through the pupil to reach the back part of the eye (known as the “retina”); the iris is the colored or pigmented part of the eye—it can be brown, blue, green, or a mixture of colors

Signs/Observed Changes in the Pet

  • Varies with tissues affected
  • Usually sudden (acute) onset of signs
  • Often a history of running through heavy vegetation, being hit by gunshot pellets or other projectiles, or being scratched by a cat
  • Trauma itself may not be observed
  • Common—corneal, scleral, or eyelid deformity; fluid buildup (known as “edema”) in affected tissues; bleeding (hemorrhage)
  • May see a retained foreign body
  • Lacerations often rapidly seal; may appear only as a blood-filled mass under the moist tissues of the eye (known as a “subconjunctival hematoma”)
  • May also see iris defects; pupil distortion; blood in the anterior chamber of the eye (the front part of the eye, between the cornea and the iris; accumulation of blood known as “hyphema”); cataract (opacity in the normally clear lens, preventing passage of light to the back part of the eye [retina]); bleeding in the vitreous (the clear, gel-like material that fills the back part of the eyeball); separation of the back part of the eye (retina) from the underlying, vascular part of the eyeball (known as the “choroid”; condition known as “retinal detachment”); and protrusion of the eyeball (known as “exophthalmia”)

Causes

  • Blunt or sharp trauma

Risk Factors

  • Preexisting visual impairment
  • Young, naive, or highly excitable pets
  • Hunting or running through heavy vegetation
  • Fighting

Treatment

Health Care

  • Depends on severity
  • Outpatient—if integrity of the eyeball is ensured
  • Sedation—consider for excited or fractious pets
  • When walking—apply an Elizabethan collar and use a harness to avoid increasing pressure in the affected eye

Injuries Considered for Medical Treatment

  • Penetrating or non-perforating wounds with no overriding or gaping of the wound edges—apply an Elizabethan collar; administer antibiotic and/or atropine eye solutions directly to the eye (“topical treatment”)
  • Penetrating or non-perforating wounds with mild gaping of wound edges or shelved edges—apply a therapeutic soft contact lens and an Elizabethan collar; administer antibiotic and/or atropine eye solutions directly to the eye (“topical treatment”)
  • Simple full-thickness, pinpoint corneal perforation with a formed anterior chamber and no uveal prolapse—sedentary pets; use a therapeutic soft contact lens and an Elizabethan collar; apply topical antibiotic and/or atropine ophthalmic solutions; reexamine a few hours after applying the lens and at 24 and 48 hours

Activity

  • Usually confined indoors (cats) or limited to leash walks until healing is complete
  • A harness is preferred to a collar, to reduce pressure on the neck and the risk of increased pressure within the eye (known as “intraocular pressure” or IOP) and leaking through the wound

Surgery

Injuries Requiring Surgical Exploration or Repair

  • Full-thickness corneal or scleral lacerations
  • Complicated injuries
  • Suspected retained foreign body or a scleral rupture involving the back of the eye
  • Simple, penetrating or non-perforating wound with edges that are moderately or overtly gaping and that are long or more than two-thirds the corneal thickness

Injuries Considered for Surgical Exploration or Repair

  • Small, simple, full-thickness corneal lacerations
  • Large conjunctival lacerations; the “conjunctiva” is the moist tissue lining the eye
  • Partial-thickness corneal or scleral lacerations in an active pet

Medications

Medications presented in this section are intended to provide general information about possible treatment. The treatment for a particular condition may evolve as medical advances are made; therefore, the medications should not be considered as all inclusive.

Antibiotics

  • Complicated wounds, those with retained plant material, and those caused by blunt trauma with tissue devitalization—infection common
  • Bacterial infection/inflammation of the tissues within the eyeball (known as “endophthalmitis”)—seen in 5% to 7% of pets with perforations; very rare in wounds that only penetrate, but do not perforate the cornea
  • Penetrating wound—topical (applied to the eye) antibiotics alone (such as neomycin, polymyxin B, and bacitracin) or gentamicin solution usually sufficient
  • Perforating wounds—systemic (administered by injection or by mouth) ciprofloxacin (dogs); topical (applied to the eye) cefazolin and fortified gentamicin or tobramycin
  • Topical (applied to the eye) ciprofloxacin eye solution—may be used instead of the combination of topical cefazolin and a fortified aminoglycoside

Anti-Inflammatory Drugs

  • Topical (applied to the eye) 1% prednisolone acetate or 0.1% dexamethasone solution—as soon as the wound is sutured or the surface is healing, if no infection is present
  • Systemic (administered by mouth) prednisone—for sutured or healing wounds when inflammation is severe; when the lens or more posterior structures are involved; when the wound is infected or not healing and control of inflammation is mandatory to preserve the eye
  • Topical (applied to the eye) nonsteroidal anti-inflammatory drugs (NSAIDs)—flurbiprofen or one of several other NSAIDs; may be used if topical steroids are not indicated (for example, infection is present) and control of inflammation is mandatory to preserve the eye

Medications to Dilate the Pupil (Known as “Mydriatics” and to Relieve Eye Pain)

  • 1% atropine eye solution—when significant constriction of the pupil (known as “miosis”) is present or inflammation is identified in the front chamber of the eye (known as “anterior chamber reaction”)

Medications to Relieve Pain (Analgesics)

  • Topical atropine or oral aspirin — may provide sufficient pain relief; use analgesics only as directed by your pet’s veterinarian
  • Butorphanol—dogs and cats; for mild pain
  • Carprofen
  • Tramadol
  • Oxymorphone—dogs and cats; for sudden (acute) severe pain; when sedation is required

Follow-Up Care

Patient Monitoring

  • Deep or long penetrating wounds that have not been sutured and perforating wounds—recheck every 24–48 hours for the first several days to ensure integrity of the eyeball, to monitor for infection, and to check control of eye inflammation
  • Superficial penetrating wounds—usually rechecked at 3- to 5-day intervals, until healed
  • Antibiotic therapy—altered according to bacterial culture and sensitivity results

Preventions and Avoidance

  • Take care when introducing new puppies to households with cats that have front claws
  • Minimize running through dense vegetation
  • Consider having a bottle of saline eyewash to irrigate or flush debris from the eye
  • Minimize visually impaired or blind dogs’ exposure to dense vegetation

Possible Complications

  • Loss of the eye or vision
  • Long-term (chronic) eye inflammation or pain

Expected Course and Prognosis

  • Most eyes with corneal lacerations or having a retained corneal foreign body are salvageable
  • The further back the injury is located in the eye, the poorer the prognosis for retention of vision
  • Poor prognosis—involvement of the sclera (the white part of the eye, it is composed of a tough covering that protects the eyeball) or uvea (the entire middle layer of the eyeball that contains the blood vessels); no light perception; perforating injuries involving the lens; significant bleeding into the vitreous (the clear, gel-like material that fills the back part of the eyeball); or separation of the back part of the eye (retina) from the underlying, vascular part of the eyeball (retinal detachment)
  • Penetrating injuries usually better prognosis than perforating injuries
  • Blunt trauma carries a poorer prognosis than sharp trauma

Key Points

  • The full extent of the injury (cataracts, retinal detachment, infection) may not be apparent until several days or weeks after the injury; therefore, long-term follow-up is necessary

Glaucoma

Glaucoma – An Overview

  • “Glaucoma” is a disease of the eye, in which the pressure within the eye is increased (pressure within the eye is known as “intraocular pressure” or IOP)
  • High intraocular pressure that causes characteristic degenerative changes in the optic nerve and retina with subsequent loss of vision; the “optic nerve” is the nerve that runs from the back of the eye to the brain; the “retina” is the innermost lining layer (located on the back surface) of the eyeball; it contains the light-sensitive rods and cones and other cells that convert images into signals and send messages to the brain, to allow for vision
  • Diagnosis—intraocular pressure greater than 25–30 mm Hg in dogs, as determined by specialized pressure measurements (such as applanation, rebound, or Schiötz tonometry) with evidence of changes in vision or appearance of the optic nerve or retina
  • Glaucoma may be “primary” or “secondary”; “primary” refers to a condition in which the pressure within the eye (intraocular pressure) increases without a preceding eye problem; “secondary” refers to a condition in which intraocular pressure increases as a complication or secondary to an eye disease or injury

Genetics

  • Dogs—abnormality of the structure of the eye that makes development of glaucoma more likely in some dogs is thought to be inherited; mode of inheritance uncertain

Signalment/Description of Pet

species

  • Dogs—primary and secondary glaucoma

Breed Predilections

  • Developmental abnormality of the angle between the iris and the cornea of the eye (known as “goniodysgenesis”)—Arctic circle breeds (such as Norwegian elkhounds, Siberian huskies, Alaskan malamutes, Akitas, Samoyeds); Bouvier des Flandres; basset hounds; chow chows; Chinese shar-peis; spaniels (such as American and English cocker spaniels, English and Welsh springer spaniels)
  • Narrow filtration angles—spaniels; chow chows; Chinese shar-peis; toy breeds (such as poodles, Maltese, and shih tzus)
  • Secondary to movement of the lens out of its normal location (lens luxations)—terriers (such as Boston terriers, cairn terriers, Manchester terriers, Dandie Dinmont terriers, Norfolk terriers, Norwich terriers, Scottish terriers, Sealyham terriers, West Highland white terriers, Parsons Jack Russell terriers, and fox terriers), Chinese shar-peis

Mean Age and Range

  • Primary glaucoma in dogs—any age; predominantly affects middle-aged dogs (4–9 years of age)
  • Secondary to movement of the lens out of its normal location (lens luxations) in dogs—usually affects young dogs (2–6 years of age)
  • Secondary to long-term (chronic) inflammation of the iris and other areas in the front part of the eye (uveitis)

Signs/Observed Changes in the Pet

  • Sudden closure of the angle between the iris and cornea of the eye (known as “acute angle closure”), leading to blockage of the flow of fluid and subsequent increased pressure within the eye—apparent pain (squinting or spasmodic blinking [known as “blepharospasm”], tenderness about the head, discharge from the eye(s), may be clear or may contain mucus); may note a cloudy or red eye; vision loss usually not noticed unless both eyes are involved
  • Secondary glaucoma—depends on primary disease
  • Inflammation of the iris and other areas in the front part of the eye (uveitis)—may note pain (for many days); red or bloodshot eyes, caused by dilated blood vessels (known as “scleral injection”); and cloudiness due to fluid buildup in the clear part of the eye (known as “corneal edema”)
  • Movement of the lens out of its normal location and into the front part of the eye (known as “anterior lens luxation”)—may note sudden (acute) pain; red or bloodshot eyes (scleral injection); and cloudiness due to fluid buildup in the clear part of the eye (corneal edema); may see lens in the anterior chamber (the front part of the eye, between the cornea and the iris), if corneal edema is not severe
  • Long-term (chronic) inflammation of the iris and other areas in the front part of the eye (uveitis). Enlarged, seemingly painless eye or a dilated pupil is common
  • Eyeball or globe enlargement (known as “buphthalmos”)—may be noticed first by owners

Sudden (Acute) Primary Glaucoma

  • High intraocular pressure (measured by your pet’s veterinarian)
  • Squinting or spasmodic blinking (blepharospasm)
  • Eyeball may recede into back of socket (known as “enophthalmos”)
  • Red or bloodshot eyes (scleral injection)
  • Cloudiness due to fluid buildup in the clear part of the eye (corneal edema)
  • Dilated pupil; the “pupil” is the circular or elliptical opening in the center of the iris of the eye—light passes through the pupil to reach the back part of the eye (known as the “retina”); the “iris” is the colored or pigmented part of the eye—it can be brown, blue, green, or a mixture of colors
  • Vision loss
  • Optic nerve may be depressed or cupped when the back of the eye is evaluated with specialized eye instruments by your pet’s veterinarian; the “optic nerve” is the nerve that runs from the back of the eye to the brain

Long-Term (Chronic) or End-Stage Glaucoma

  • Eyeball or globe enlargement (buphthalmos)
  • Lines that develop on the inner lining of the cornea, the normally clear part of the front of the eye (known as “Descemet’s streaks” or “Haab’s striae”)
  • Partial movement of the lens out of its normal location (known as a “lens subluxation”) with a resultant “crescent” appearing in the area of the iris (known as an “aphakic crescent”)
  • Wasting away or decrease in size of the cells in the optic nerve head (known as “optic nerve head atrophy”); the “optic nerve” is the nerve that runs from the back of the eye to the brain
  • Death of tissue in the retina (known as “retinal necrosis”)—detected increased reflectivity in the back of the eye when the veterinarian performs an examination

Glaucoma Induced by Inflammation of the Iris and Other Areas in the Front Part of the Eye (Uveitis)

  • Elevated intraocular pressure (measured by your pet’s veterinarian)
  • Red or bloodshot eyes (scleral injection)
  • Cloudiness due to fluid buildup in the clear part of the eye (corneal edema)
  • Inflammatory debris in the front part of the eye, between the cornea and the iris (anterior chamber)
  • Constricted or miotic pupil may or may not be seen; the “pupil” is the circular or elliptical opening in the center of the iris of the eye; light passes through the pupil to reach the back part of the eye (known as the “retina”); the “iris” is the colored or pigmented part of the eye—it can be brown, blue, green, or a mixture of colors
  • Scar tissue between the iris and the lens of the eye (known as “posterior synechia”) may or may not be present; the “lens” is the normally clear structure directly behind the iris that focuses light as it moves toward the back part of the eye (retina)
  • Bulging of the iris toward the front of the eye (known as “iris bombé”) may or may not be recent

Causes

  • Primary glaucoma—structural abnormalities of the eye involving the filtration angle (the “filtration angle” is the area where the cornea, sclera, and iris meet; it contains a structure that allows fluid to flow out of the eye, thus maintaining normal pressure within the eye; in primary glaucoma, the structure is abnormal so fluid does not flow adequately and the pressure within the eye increases)
  • Secondary glaucoma—blockage of the flow of aqueous humor out of the eye; the “aqueous humor” is the transparent liquid that fills the front part of the eyeball

Risk Factors

  • Inflammation of the front part of the eye, including the iris (known as “anterior uveitis”)
  • Movement of the lens out of its normal location (lens luxation)
  • Blood in the anterior chamber of the eye (the front part of the eye, between the cornea and the iris; accumulation of blood known as “hyphema”)
  • Tumor or cancer within the eyeball
  • Medications applied to the eye directly to dilate the pupil (known as “mydriatics”)—may lead to sudden (acute) glaucoma in susceptible pets
  • Primary glaucoma in dogs—consider all cases to involve both eyes, even if one eye has normal intraocular pressure at the time of evaluation; a veterinary eye doctor (ophthalmologist) should examine the apparently normal eye for filtration angle abnormalities to determine the risk for future glaucoma

Treatment

Health Care

  • Sudden (acute) glaucoma in dogs—inpatient medical care
  • After discharge from the veterinary hospital—reevaluate every 1–2 days for 1 week to monitor for return of increased intraocular pressure

Surgery

  • Cases with primary glaucoma or glaucoma due to movement of the lens out of its normal location (lens luxation) induced are best treated surgically
  • Primary glaucoma in dogs—less than 10% of affected pets undergoing medical treatment alone will have vision remaining at the end of the first year following diagnosis
  • Various surgical procedures may be performed to increase the flow of aqueous humor out of the eye; to decrease production of aqueous humor in the eye; procedures performed attempt to maintain normal intraocular pressure and vision; the “aqueous humor” is the transparent liquid that fills the front part of the eyeball
  • Surgical removal of lens that has moved forward in the eye (anterior lens luxation) may result in a visual eye, as well as help lower intraocular pressure
  • Blind, painful eyes—surgically remove the eye (known as “enucleation”); may remove the inner parts of the eye surgically, leaving the eyeball and place a prosthesis in the eye (known as “evisceration and intraocular prosthesis implantation”) in some cases

Medications

Medications presented in this section are intended to provide general information about possible treatment. The treatment for a particular condition may evolve as medical advances are made; therefore, the medications should not be considered as all inclusive.

Sudden (Acute) Primary Glaucoma in Dogs

  • Emergency medical treatment may include one or more of the following:
  • Medications applied to the eye directly to cause the pupil to constrict (known as “topical miotics”)—latanoprost 0.005% (Xalatan), travoprost 0.004% (Travatan), or bimatoprost 0.03% (Lumigan); 2% pilocarpine solution; 0.25% demecarium bromide; treatment aimed at improving aqueous outflow
  • Topical beta-adrenergic antagonists—timolol maleate 0.5%, levobunalol 0.5%, betaxolol 0.5%; reduce aqueous humor production; the “aqueous humor” is the transparent liquid that fills the front part of the eyeball
  • Carbonic anhydrase inhibitor (administered by mouth)—methazolamide; reduce production of aqueous humor
  • Carbonic anhydrase inhibitors (applied to the eye directly)—dorzolamide 2% (TruSopt), brinzolamide 1% (Azopt); reduce aqueous humor production
  • Medications to remove fluids from the body (known as “hyperosmotic agents”)—mannitol or glycerin; dehydrate the vitreous humor; the “vitreous” is the clear, gel-like material that fills the back part of the eyeball (between the lens and the retina)

Glaucoma Secondary to Movement of the Lens Out of its Normal Location Toward the Front of the Eye (Anterior Lens Luxation) or Inflammation of the Iris and Other Areas in the Front Part of the Eye (Uveitis) in Dogs

  • Treated like primary glaucoma
  • Medications to cause the pupil to constrict (miotic agents) should not be used
  • Steroids applied to the eye directly (known as “topical steroids”)—used to reduce inflammation if no changes of the cornea (the clear outer layer of the front of the eye) characterized by the presence of ulcers, with or without inflammation (condition known as “ulcerative keratitis”)

Long-Term (Chronic) Smoldering Inflammation of the Iris

  • Steroids applied to the eye directly (topical steroids)
  • Topical beta-blockers; reduce aqueous humor production; the “aqueous humor” is the transparent liquid that fills the front part of the eyeball
  • Carbonic anhydrase inhibitor diuretics or topical carbonic anhydrase inhibitors to reduce production of aqueous humor

Follow-Up Care

Patient Monitoring

  • Intraocular pressure—monitored often and regularly after starting initial therapy; if low intraocular pressure (known as “hypotensive ocular pressure”) is maintained for many weeks, slowly taper drug therapy (as directed by your pet’s veterinarian)
  • Monitor for drug reactions

Preventions and Avoidance

  • Primary glaucoma—consider all cases to involve both eyes, even if one eye has normal intraocular pressure at the time of evaluation; a veterinary eye doctor (ophthalmologist) should examine the apparently normal eye for filtration angle abnormalities to determine the risk for future glaucoma
  • Prophylactic therapy for the apparently unaffected eye—0.25% demecarium bromide or 0.005% latanoprost or 0.5% timolol maleate or 2% dorzolamide; delays onset of glaucoma in second susceptible eye

Possible Complications

  • Blindness
  • Long-term (chronic) eye pain

Expected Course and Prognosis

  • Long-term (chronic) disease that requires constant medical treatment (even with surgical intervention)
  • With medical treatment only—most affected pets ultimately go blind
  • Surgical treatment—better chance of retaining vision longer; most affected pets do not remain visual for more than 2 years after initial diagnosis
  • Secondary glaucoma due to movement of the lens out of its normal location (lens luxation)—may carry a fair prognosis with successful surgical removal of the luxated lens
  • Secondary glaucoma due to anterior uveitis—may carry a fair prognosis with control of inflammation of the iris and other areas in the front part of the eye

Key Points

  • Primary glaucoma is a disease that involves both eyes; over 50% of pets develop glaucoma in the other eye within 8 months without prophylactic therapy
  • 40% or more of dogs will be blind in the affected eye within the first year, no matter what is done medically or surgically

Conjunctivitis

Conjunctivitis – An Overview

  • Inflammation of the moist tissues of the eye (known as the “conjunctiva”); the conjunctiva is the vascularized moist tissue (mucous membrane) that covers the front part of the eyeball or globe, up to the edge of the cornea (known as the “bulbar conjunctiva”) and lines the lids and third eyelid (known as the “palpebral conjunctiva”)

Signalment/Description of Pet

Breed Predilections

  • Breeds susceptible to allergic or immune-mediated skin diseases (such as “atopy”) tend to have more problems with allergic inflammation of the moist tissues of the eye (conjunctivitis) or “dry eye” (known as “keratoconjunctivitis sicca” or KCS); “atopy” is a disease in which the dog is sensitized (or “allergic”) to substances found in the environment (such as pollen) that normally would not cause any health problems

Signs/Observed Changes in Pet

  • Squinting or spasmodic blinking (known as “blepharospasm”)
  • Redness of the moist tissues of the eye (known as “conjunctival hyperemia”)
  • Discharge from the eye(s); may be clear or may contain mucus and/or pus
  • Fluid buildup (known as “edema”) of the moist tissue covering of the eyeball (bulbar conjunctiva), around the cornea (condition known as “chemosis”)
  • Follicle formation; the “follicles” are accumulations of lymphoid tissue located at the moist tissue surface of the third eyelid and the eyelids, causing a “cobblestone” appearance; lymphoid tissue contains lymphocytes, a type of white blood cell that are involved in allergies and response to irritants

Causes

Bacterial Causes

  • Primary condition (that is, not secondary to another condition such as “dry eye” [keratoconjunctivitis sicca or KCS])—rare
  • Newborn inflammation of the moist tissues of the eye (conjunctivitis)—accumulation of discharge, often associated with a bacterial or viral infection; seen before the eyelids separate or open

Viral Causes

  • Canine distemper virus
  • Canine herpesvirus-1
  • Canine adenovirus-2

Immune-Mediated Causes

  • Allergic conjunctivitis—especially in atopic pets; “atopy” is a disease in which the animal is sensitized (or “allergic”) to substances found in the environment (such as pollen) that normally would not cause any health problems
  • Follicular conjunctivitis—inflammation of the moist tissues of the eye (conjunctivitis) characterized by accumulations of lymphoid tissue located at the moist tissue surface of the third eyelid and the eyelids, causing a “cobblestone” appearance; lymphoid tissue contains lymphocytes, a type of white blood cell that are involved in allergies and response to irritants; especially in dogs younger than 18 months of age, secondary to long-term (chronic) antigenic stimulation (that is, the substance to which the immune system is responding and producing antibodies)
  • Plasma-cell conjunctivitis—inflammation of the moist tissues of the eye (conjunctivitis) characterized by the presence of plasma cells (a specialized type of white blood cell; plasma cells are lymphocytes that have been altered to produce immunoglobulin, an immune protein or antibody necessary for fighting disease); especially in German shepherd dogs
  • Related to generalized (systemic) immune-mediated diseases—such as pemphigus, in which the body attacks its own tissues

Cancer or Pseudocancer Causes

  • Tumors involving the moist tissues of the eye (conjunctiva)—rare; include melanoma, hemangioma, hemangiosarcoma, lymphoma, papilloma, and mast-cell tumors
  • Lesions that appear to be cancer, but are not cancerous (known as “pseudocancer”)—inflammation of the border between the cornea (the clear part of the eye, located in the front of the eyeball) and the sclera (the white part of the eye, it is composed of a tough covering that protects the eyeball) characterized by the presence of nodules (condition is known as “nodular episcleritis” [also-called “fibrous histiocytoma,” “ocular nodular granuloma,” and “conjunctival pseudotumor”]; most commonly seen in collies and mixed collies; believed to be immune-mediated; usually appears as a pink mass

Secondary to Disease of the Tissues Surrounding the Eye (Known as “Adnexa,” Such as Eyelids, Third Eyelid, and Tear Glands)

  • Lack of normal tear film (known as “aqueous tear film deficiency”); “dry eye” (KCS)
  • Lid diseases (such as “entropion,” in which the eyelid curls inward, allowing facial hair to rub the eye; “ectropion,” in which the eyelid is turned outward) and lash diseases (such as “distichiasis,” in which two rows of eyelashes are present on a single eyelid; “ectopic cilia,” in which one or more eyelashes grows in an unusual location [may grow through the conjunctiva, leading to irritation of the eye])—may lead to clinical signs of inflammation of the moist tissues of the eye (conjunctivitis)
  • Secondary to blockage of the outflow portion of the drainage system that normally moves tears to the nasal passages (known as the “nasolacrimal system”), such as an obstructed nasolacrimal duct or lack of normal openings on the eyelids into the tear drainage system (known as “imperforate puncta”)

Secondary to Trauma or Environmental Causes

  • Foreign body located in the moist tissues of the eye
  • Irritation from dust, chemicals, or eye medications

Secondary to Other Eye Diseases

  • Disorder of the cornea (the clear outer layer of the front of the eye) characterized by the presence of ulcers, with or without inflammation (condition known as “ulcerative keratitis”)
  • Inflammation of the front part of the eye, including the iris (known as “anterior uveitis”)
  • Disease of the eye, in which the pressure within the eye is increased (known as “glaucoma”)

Other Causes

  • Ligneous conjunctivitis (inflammation of the moist part of the eye, characterized by thick, opaque conjunctiva)—young, female Doberman pinschers

Risk Factors

  • Exposure to dogs with canine distemper virus, herpesvirus-1, or adenovirus-2 infections

Treatment

Health Care

  • Primary—often outpatient
  • Secondary to other diseases (such as inflammation of the front part of the eye, including the iris [anterior uveitis} and corneal ulceration, with or without inflammation [ulcerative keratitis])—may need hospitalization while the underlying problem is diagnosed and treated

Activity

  • Primary—usually no restriction
  • Suspected contact irritant or sudden (acute) allergic disease—prevent (if possible) contact with the agent causing the irritation or allergy
  • Do not expose pets to other dogs to decrease risk of spread of infectious causes (such as canine distemper virus) of inflammation of the moist tissues of the eye (conjunctivitis)

Diet

  • Suspected underlying skin disease and/or food allergy—food elimination diet recommended; “elimination diet” is a diet that does not contain substances that the animal normally eats and is free of additives

Surgery

  • Blockage of the outflow portion of the drainage system that normally moves tears to the nasal passages (known as the “nasolacrimal system”), such as an obstructed nasolacrimal duct—surgical repair is difficult; treatment often not recommended
  • Cancer involving the moist tissues of the eye (“conjunctival cancer”)—may involve surgical removal of the tumor followed by radiation therapy; freezing (known as “cryotherapy”); or heating of the tissues using radiofrequency waves (known as “radiofrequency hyperthermia”); may involve surgical removal of the eyeball and associated tissues (known as “enucleation”), depending on the type of tumor and the extent of involvement

Medications

Medications presented in this section are intended to provide general information about possible treatment. The treatment for a particular condition may evolve as medical advances are made; therefore, the medications should not be considered as all inclusive.

Bacterial Infections

  • Antibiotics based on bacterial culture and sensitivity results
  • Antibiotics may be applied directly to the moist tissues of the eye (“topical treatment”) or may be given by mouth (“systemic treatment”)
  • Initial treatment—broad-spectrum topical antibiotic or specific antibiotic based on results of microscopic examination of discharge and/or conjunctival scraping, while waiting for bacterial culture and sensitivity results; may try treatment based on experience with other cases of conjunctivitis, performing a bacterial culture and sensitivity only if the pet does not respond to selected treatment
  • Topical triple antibiotic or chloramphenicol—if cocci (general type of bacteria) seen on microscopic examination of discharge and/or conjunctival scraping
  • Gentamicin or tobramycin—if rods (general type of bacteria) seen on microscopic examination of discharge and/or conjunctival scraping
  • Ciprofloxacin or other quinolone antibiotics—may be useful for severe bacterial inflammation of the moist tissues of the eye (conjunctivitis)
  • Systemic antibiotics—occasionally indicated, especially for more generalized disease (such as inflammation of the moist tissues of the eye [conjunctivitis] associated with skin infection characterized by the presence of pus [known as “pyoderma”])

New Born Conjunctivitis

  • Depends on severity
  • Topical steroids— applied directly to the moist tissues of the eye; 0.1% dexamethasone; improve clinical signs of allergic, follicular conjunctivitis (characterized by accumulations of lymphoid tissue located at the moist tissue surface of the third eyelid and the eyelids, causing a “cobblestone” appearance), and plasma-cell conjunctivitis (characterized by the presence of plasma cells); improvement often temporary
  • Treatment of any underlying disease (such as atopy) often improves clinical signs; “atopy” is a disease in which the animal is sensitized (or “allergic”) to substances found in the environment (such as pollen) that normally would not cause any health problems
  • Other steroids—1% prednisolone acetate; betamethasone; hydrocortisone

Follow-Up Care

Patient Monitoring

  • Recheck shortly after beginning treatment (at 5–7 days); then recheck as needed

Preventions and Avoidance

  • Treat any underlying disease that may make the eye disease worse—allergic or immune-mediated skin disease; “dry eye” (KCS)
  • Vaccination against canine distemper virus

Expected Course and Prognosis

  • Bacterial infection/inflammation of the moist tissues of the eye (conjunctivitis)—usually resolves with appropriate administration of antibiotics; if an underlying disease is found (such as “dry eye” [KCS]), resolution may depend on appropriate treatment and resolution of the disease
  • Immune-mediated diseases—diseases tend to be controlled, not cured; may require long-term (chronic) treatment with steroids at the lowest dose possible

Key Points

  • If a large amount of discharge is noted, gently clean the eyes before administering treatment
  • If both eye solutions and eye ointments are prescribed, apply the solution(s) before applying the ointment(s)
  • If several eye solutions are prescribed, wait several minutes between treatments
  • Call for instructions if the condition worsens, which indicates that the condition may not be responsive to treatment or may be progressing or that the animal may be having an adverse reaction to a prescribed medication
  • An Elizabethan collar should be placed on the pet, if self-trauma occurs

Cataracts

Cataracts – An Overview

  • Opacity in the lens; the lens is the normally clear structure directly behind the iris (the colored part of the eye) that focuses light as it moves toward the back part of the eye (retina); if opacity is complete, it prevents passage of light to the back part of the eye (retina), leading to blindness in the affected eye
  • “Cataract”—may refer to a lens that is entirely opaque or to a localized opacity within the lens; does not imply cause

Genetics

  • Inheritance has been established for many dog breeds; most common mode of inheritance—autosomal recessive
  • The number of individuals with genetic cataracts varies significantly between breeds; it has been reported to be as high as 10% in some breeds
  • Inheritance has been established in the Himalayan (cat)—autosomal recessive

Signalment/Description of Pet

Breed Predilections

  • Over 135 dog breeds are suspected of having increased likelihood of having hereditary cataracts

Mean Age and Range

  • Depend on cause
  • Cataracts can develop at any age
  • Genetic cataracts can develop as early as 6 months of age

Signs/Observed Changes in Pet

  • Opacity or white appearance of the lens
  • Related to the degree of vision impairment
  • Vision loss may be noticed when cataracts are present in both eyes
  • Cataract caused by diabetes mellitus (sugar diabetes)—may see signs of diabetes, such as increased urination (known as “polyuria”), increased thirst (known as “polydipsia”), and weight loss
  • Cloudiness in the eye (specifically the lens) noticed before vision impairment—may be related to sclerosis, rather than cataract formation; “sclerosis” is a normal aging change in the lens due to changes in the lens fibers, it apparently has little to no effect on vision
  • May be associated with inflammation of the front part of the eye, including the iris (known as “anterior uveitis”)—typically see cloudiness of aqueous humor (the “aqueous humor” is the transparent liquid that fills the front part of the eyeball) due to increased protein content and suspended cellular debris (condition known as “aqueous flare”); scar tissue between the iris and the lens of the eye (known as “synechiae”); and decreased pressure within the eye (known as “low intraocular pressure”)

Causes

  • Heredity—most common cause in dogs
  • Diabetes mellitus (sugar diabetes)
  • Inflammation of the front part of the eye, including the iris (anterior uveitis)—secondary to formation of scar tissue between the iris and the lens of the eye (synechia) or altered aqueous humor (the transparent liquid that fills the front part of the eyeball) composition
  • Trauma—injury to the eye, where something penetrates the outer surface of the eye and disrupts the anterior lens capsule, most commonly a cat-claw injury especially in puppies.
  • Senile—age-related; slowly progressive cataract in senior pets
  • Congenital (present at birth)—inherited cataract; damage to the developing lens or eye while the puppy is in the uterus; may be associated with other congenital eye abnormalities
  • Surgery
  • Toxic substances
  • Radiation
  • Low levels of calcium in the blood (known as “hypocalcemia”)
  • Nutrition—use of unbalanced milk-replacer diet in bottle-fed puppies
  • Electric shock—chewing electrical cords or lightning strike

Risk Factors

  • Genetics
  • Diabetes mellitus (sugar diabetes) in dogs
  • Long-term (chronic) inflammation of the front part of the eye, including the iris (anterior uveitis
  • Progressive retinal atrophy (a group of eye diseases characterized by generalized deterioration of the retina, becoming increasingly worse over time); the “retina” is the back part of the eye; the retina contains the light-sensitive rods and cones and other cells that convert images into signals and send messages to the brain, to allow for vision

Treatment

Activity

  • For safety, blind pets should not be allowed access to an in-ground swimming pool or elevated decks with open railings; use caution near stairs
  • Restrict outside activity to fenced yards or leash-walks

Surgery

  • Phacoemulsification is a surgical procedure in which ultrasonic vibrations are used to fragment and liquefy the lens, in order to remove the lens material; procedure of choice
  • Ideal time for cataract surgery is the immature or early mature cataract stageIntraocular lenses—may be implanted safely at the time of surgery, so the pet will not suffer extreme farsightedness

Medications

Medications presented in this section are intended to provide general information about possible treatment. The treatment for a particular condition may evolve as medical advances are made; therefore, the medications should not be considered as all inclusive.

  • Topical (applied directly to the eye) anti-inflammatory medication is recommended to prevent and treat lens-induced inflammation of the front part of the eye, including the iris (anterior uveitis); topical anti-inflammatory medications include flurbiprofen or diclofenac or a topical steroid, such as prednisolone 1% or dexamethasone 0.1%
  • Topical atropine for lens-induced inflammation of the front part of the eye, including the iris (anterior uveitis)
  • Non-steroidal anti-inflammatory drugs (NSAIDs) administered by mouth (oral administration) are used to treat lens-induced inflammation of the front part of the eye, including the iris (anterior uveitis); examples include carprofen, meloxicam, and tepoxalin

Follow-Up Care

Patient Monitoring

  • Early immature cataracts—monitor regularly for progression of cataracts, in order to select the ideal time for surgery and avoid complications associated with cataracts
  • Post-operative monitoring by the surgeon is critical for success

Preventions and Avoidance

  • Do not breed pets with cataracts

Possible Complications

  • Lens-induced inflammation of the front part of the eye, including the iris (anterior uveitis)
  • Secondary glaucoma (in which the pressure within the eye [intraocular pressure] is increased secondary to inflammation in the front part of the eye)
  • Separation of the back part of the eye (retina) from the underlying, vascular part of the eyeball (known as the “choroid”; condition known as “retinal detachment”)
  • Movement of the lens out of its normal location (known as “lens luxation”)

Expected Course and Prognosis

  • Long-term prognosis following cataract surgery is very good
  • Some pets have increased risk for post-operative complications, such as those with pre-existing inflammation of the front part of the eye, including the iris (anterior uveitis), even if medically controlled; genetic likelihood of developing glaucoma; retinal abnormalities

Key Points

  • Cataract surgery is performed routinely with an overall 80–90% success rate
  • Once the cataract(s) is/are removed, they cannot return
  • Artificial lens implants will restore essentially normal vision
  • Evaluation for surgery should be done early in the course of cataract development to avoid complications that may result in the cataract becoming inoperable, to allow time to plan for the surgery, and, in some cases, to eliminate the need and extra cost for an ultrasound examination of the eye and an evaluation of the electrical responses in the retina (procedure known as an “electroretinogram”)

Osteosarcoma

Osteosarcoma – An Overview

  • Most common primary bone tumor in dogs
  • “Appendicular” is an adjective relating to the limbs; “axial” is an adjective relating to the head and trunk of the body
  • Osteosarcoma typically affects the appendicular skeleton of large- to giant-breed dogs; may be seen in the axial skeleton (composed of skull, spine, ribs, and sternum)
  • Cancerous (malignant) tumor, with spread to the lungs (known as “lung metastases”) in more than 90% of dogs at the time of diagnosis; lung metastases may be microscopic
  • Osteosarcoma may spread to soft tissues, such as the skin, kidney, and liver
  • Osteosarcoma accounts for up to 85% of primary bone tumors in dogs

Genetics

  • Appears to be inherited in giant breeds, such as Scottish deerhounds and Irish wolfhounds
  • Increased likelihood of developing osteosarcoma does occur in some breeds
  • Breed size and rate of maturity may be more important than breed or family line

Signalment/Description of Pet

Breed Predilections

  • large- to giant-breed dogs

Mean Age and Range

  • bimodal peak at 2 years and 7 years; reported as young as 6 months of age.

Predominant Sex

  • no strong indication that a particular sex is more likely to develop osteosarcoma than the other sex

Signs/Observed Changes in Pet

  • Depend on site
  • Signs may be subtle
  • Appendicular skeleton (limbs)—welling, lameness, and pain common
  • Axial skeleton (skull, spine, ribs, sternum)—localized swelling, detectable mass, pain
  • Other complaints—lack of appetite (inappetence) and sluggishness (lethargy)
  • A firm, painful swelling of the affected site common
  • Degree of lameness—varies from mild to non–weight-bearing
  • Buildup of fluid (known as “edema”) around affected area
  • Fractures occurring at the site of weakened bone (known as “pathologic fractures”) are rare

Causes

  • Unknown

Risk Factors

  • Dogs—large- to giant-breed dogs; metallic implants at fracture-repair sites; history of exposure to ionizing radiation
  • Early spay/neuter

Treatment

Health Care

  • Diagnostic evaluation—outpatient
  • Surgery and the first chemotherapy treatment—inpatient
  • Subsequent chemotherapy—outpatient
  • Manage pain, as needed
  • Radiation therapy will decrease pain effectively in dogs

Activity

  • Restricted after surgery, until adequate healing has occurred

Diet

  • Dietary management is not required
  • Weight lost may benefit amputees in general

Surgery

Appendicular Sites (Relating to the Limbs)

  • Amputation of affected limb—limb amputated at the forequarter (including the scapula and shoulder joint) or hip
  • Limb-sparing or salvage therapy—used for osteosarcoma of the distal radius (bone in the lower front leg); available at a limited number of referral hospitals
  • Chemotherapy—recommended after either surgical procedure

Axial Sites (Relating to the Head and Trunk of the Body)

  • Amputation of affected limb—limb amputated at the forequarter (including the scapula and shoulder joint) or hip
  • Limb-sparing or salvage therapy—used for osteosarcoma of the distal radius (bone in the lower front leg); available at a limited number of referral hospitals
  • Chemotherapy—recommended after either surgical procedure

Soft Tissue Sites (Tissues Other than Bone)

  • Amputation of affected limb—limb amputated at the forequarter (including the scapula and shoulder joint) or hip
  • Limb-sparing or salvage therapy—used for osteosarcoma of the distal radius (bone in the lower front leg); available at a limited number of referral hospitals
  • Chemotherapy—recommended after either surgical procedure

Metastasectomy (Surgical Removal of Metastasis)

  • Surgical removal of metastasis to the lungs (known as “pulmonary metastasectomy”)—has been described; indicated in dogs that: (1) had a long disease-free interval (over 300 days) after diagnosis; (2) have only 1–2 detectable lung nodules based on computed tomography scan (CT scan)
  • Inoperable cancer—radiation therapy to control signs and improve the pet’s condition, but not to cure (known as “palliative intent”)
  • Pain management with medications such as nonsteroidal anti-inflammatory drugs (NSAIDs), opiods, or bisphosphonates may improve quality of life and thus prolong survival

Medications

Medications presented in this section are intended to provide general information about possible treatment. The treatment for a particular condition may evolve as medical advances are made; therefore, the medications should not be considered as all inclusive

  • Post-surgical chemotherapy with either platinum-based protocol (cisplatin, carboplatin), or doxorubicin is the current standard of care
  • Palliative medication is intended to improve the pet’s condition and quality of life, it is not a cure for the cancer; these drugs are used to control pain and/or decrease inflammation; options include: aspirin, piroxicam, or other nonsteroidal anti-inflammatory drugs; acetaminophen with or without codeine, tramadol or a fentanyl patch—not all of these drugs can be used in combination; always consult your pet’s veterinarian for the most appropriate pain management for your pet

Follow-Up Care

Patient Monitoring

  • Monitor for reduction of bone-marrow activity (known as “myelosuppression”), resulting in low number of red blood cells, white blood cells, and/or platelets; should have a complete blood count (CBC) performed 7–10 days after chemotherapy
  • Take chest x-rays (radiographs) every 2–3 months after surgery
  • Take x-rays (radiographs) of graft site for cases with limb-sparing or salvage therapy every 2–3 months after surgery, because local recurrence is possible after limb salvage

Possible Complications

  • Spread of cancer (metastasis) to lungs, bone, and soft tissue sites
  • Hypertrophic osteopathy (a bone disorder that causes painful swelling of bone and lameness) with spread of cancer to lungs (lung metastases)
  • Pets that undergo limb-sparing or limb-salvage procedures may develop infections, local recurrence of the cancer, or failure of the surgical implants
  • Amputees rarely show complications secondary to arthritis in the other legs

Expected Course and Prognosis

  • Prognosis is poor; achievable goals should be to relieve discomfort and prolong life
  • Median survival without treatment, with amputation alone, or with palliative radiation therapy alone—approximately 4 months
  • Median survival with surgery and chemotherapy—10 months
  • Osteosarcoma of the lower jaw (known as “mandibular osteosarcoma”)—less aggressive than other sites; 1-year median survival time with surgery alone—71% reported in one study

Key Points

  • The most common primary bone tumor in dogs
  • This disease has an aggressive biologic behavior; therapy should be directed at the painful bone tumor (using either surgery or radiation therapy) as well as at metastatic disease (using chemotherapy)
  • Prognosis is poor; achievable goals should be to relieve discomfort and prolong life
  • Cure is unlikely

Transitional Cell Carcinoma of the Urinary Tract

Transitional Cell Carcinoma of the Urinary Tract – An Overview

  • The urinary tract consists of the kidneys, the ureters (the tubes running from the kidneys to the bladder), the urinary bladder (that collects urine and stores it until the pet urinates), and the urethra (the tube from the bladder to the outside, through which urine flows out of the body)
  • Transitional cell carcinoma is a cancer arising from the transitional epithelium within the kidney, ureters, urinary bladder, urethra, prostate, or vagina; the transitional epithelium is a specialized type of lining in the urinary tract that contracts or stretches in response to the size of the bladder and other organs

Signalment/Description of Pet

Breed Predilections

  • Scottish terriers, West Highland white terriers, Shetland sheepdogs, American Eskimo dogs, and dachshunds; may occur in any breed

Mean Age and Range

  • Dogs—8 years; range, 1–15+ years of age
  • Middle-aged to old, spayed, female small-breed dogs most commonly reported

Predominant Sex

  • Female

Signs/Observed Changes in Pet

  • Similar to those of bacterial urinary tract infection or the presence of stones in the urinary tract (known as “urolithiasis”); for pets showing temporary or no response to appropriate antibiotics, consider transitional cell carcinomaRecurrent straining with slow, painful discharge of urine (known as “stranguria”); abnormal frequent passage of urine (known as “pollakiuria”); blood in the urine (known as “hematuria”); difficulty urinating (known as “dysuria”); inability to control urination or leaking urine (known as “urinary incontinence”); or any combination of these signs
  • Physical examination findings often normal
  • Mass—occasionally may be felt in the abdomen at the location of the urinary bladder
  • Urethral or vaginal transitional cell carcinoma—may be able to feel mass during rectal examination
  • Rarely enlarged intrapelvic or sublumbar lymph nodes—may be able to feel during rectal examination

Causes and Risk Factors

  • Scottish terrier; obesity; environmental carcinogens (substances that cause cancer); long-term (chronic) exposure to certain flea-control products (such as organophosphates or carbamates); and rarely, long-term treatment or a large bolus dose of cyclophosphamide (a chemotherapeutic drug)

Treatment

Health Care

  • Outpatient—stable pets; initial workup generally takes 1–2 days, so hospitalization may be more convenient
  • Seek advice from a veterinary oncologist prior to initiating treatment and consider current recommendations
  • Radiation therapy

Activity

  • Normal

Diet

  • Normal, unless pet also has kidney failure

Surgery

Appendicular Sites (Relating to the Limbs)

  • Surgery for transitional cell carcinoma can be challenging as the tumor easily sheds cancer cells; these cells can be spread into the abdomen during surgery
  • Surgery may result in a cure, if the mass can be removed completely
  • Wide surgical excision (that is, surgically removing the tumor and wide borders of apparently normal tissue) is necessary; up to 50% of the urinary bladder may be removed surgically with minimal loss of function
  • Placement of a catheter from the bladder and exiting through the abdominal wall to allow urine to be removed from the body (procedure known as “tube cystostomy”)—may greatly prolong survival times by bypassing blockage of the urethra (known as “urethral obstruction”)
  • Urethral stenting (placing a medical “tube” inside the urethra) may prolong survival by temporarily relieving blockage of the urethra, and thereby, allowing the pet to urinate

Medications

Medications presented in this section are intended to provide general information about possible treatment. The treatment for a particular condition may evolve as medical advances are made; therefore, the medications should not be considered as all inclusive

  • Chemotherapy—piroxicam (Feldene), cisplatin (dogs), mitoxantrone (as single agents or as combination therapy for certain drugs); piroxicam and cisplatin cannot be combined because of kidney toxicity; other agents (doxorubicin or doxorubicin/cyclophosphamide combination) may have activity
  • Antibiotics—administered as necessary for secondary urinary tract infections

Follow-Up Care

Patient Monitoring

  • X-rays (radiographs) using contrast media in the bladder (known as “contrast cystography”) or ultrasound examination—every 6–8 weeks; assess response to treatment and screen for spread of cancer into the lymph nodes (known as “lymph-node metastases”)
  • Chest x-rays(radiographs)—every 2–3 months; detect spread of cancer into the lungs (known as “pulmonary metastatic disease”)

Possible Complications

  • Blockage of the urethra (the tube from the bladder to the outside, through which urine flows out of the body) or ureters (the tubes running from the kidneys to the bladder), and kidney failure
  • Spread of cancer (metastasis) to regional lymph nodes, lungs, or bone
  • Recurrent urinary tract infection
  • Lack of control of urination or urine leakage (urinary incontinence)
  • Reduction of bone-marrow activity (known as “myelosuppression”), resulting in low number of red blood cells, white blood cells, and/or platelets or gastrointestinal toxicity secondary to chemotherapy
  • Gastrointestinal ulceration secondary to piroxicam therapy

Expected Course and Prognosis

  • Long-term prognosis grave
  • Progressive disease probable
  • Median survival—no treatment, 4–6 months; with treatment, 6–12 months

Key Points

  • Long-term prognosis is poor, but control of signs to make the pet more comfortable (known as “palliation”) is often attainable
  • The tumor usually cannot be removed surgically in dogs

Rabies

Rabies – An Overview

A severe, invariably fatal, viral inflammation of the gray matter of the brain (known as “polioencephalitis”) of warm-blooded animals, including humans; “gray matter” is the nerve tissue of the brain that contains the nerve cell bodies.

Signalment/Description of Pet

Species

  • All warm-blooded mammals, including dogs, cats, and people.
  • United States—five strains of rabies virus are found in the skunk, raccoon, coyote, fox, and insectivorous bat populations; all five strains can be transmitted to dogs and cats.

Mean Age and Range

  • None, but adult animals that come in contact with wildlife are at most risk

Signs/Observed Changes in the Pet

  • Quite variable; atypical presentation is the rule rather than the exception
  • Three progressive stages of disease—(1) prodromal stage—early signs of disease; signs may include change in behavior, apprehension, nervousness, seeking solitude; (2) furious stage—signs may include irritability, excitability, avoidance of light (known as “photophobia”), and viciousness (biting, attacking); and (3) paralytic stage—also known as the “dumb form” of rabies; signs may include paralysis of various parts of the body (determined by location of original site of exposure to the rabies virus, such as a bite wound), change in voice (known as “dysphonia”), excessive salivation/drooling, and choking sounds; final signs include coma and death
  • 90% of cats with rabies have the furious form of disease
  • Change in attitude—pet seeks solitude; apprehension, nervousness, anxiety; unusual shyness or aggressiveness
  • Erratic behavior—biting or snapping; licking or chewing at site of wound; biting at cage; wandering and roaming; excitability; irritability; viciousness
  • Disorientation
  • Muscular incoordination; seizures; inability to move voluntarily (known as “paralysis”)
  • Change in tone of bark
  • Excess salivation or frothing
  • Paralysis of the lower jaw (mandible) and voice box or larynx; dropped jaw
  • Inability to swallow
  • Fever
  • Dilated pupils—unresponsive to light; unequal size of the pupils (known as “anisocoria”)

Causes

  • Rabies virus

Risk Factors

  • Exposure to wildlife, especially skunks, raccoons, bats, and foxes
  • Lack of adequate vaccination against rabies
  • Bite or scratch wounds from unvaccinated dogs, cats, or wildlife
  • Exposure to aerosols in bat caves
  • Pets that do not have the ability to develop a normal immune response (known as an “immunocompromised pet”)—use of modified live virus rabies vaccine

Treatment for Rabies

Healthcare

  • Strictly inpatient for pet suspected of being exposed to rabies or having rabies
  • Administer nursing care with extreme caution
  • No treatment for rabies
  • Once the diagnosis is certain, euthanasia is indicated

Activity

  • Confine to secured quarantine area with clearly posted signs indicating suspected rabies
  • Runs or cages should be locked; only designated people should have access
  • Feed and water without opening the cage or run door (in other words, pass food and water bowls into the cage or run through specialized access points designed for such use)

Diet

  • Soft, moist food; most affected pets will not eat

Surgery

  • Generally none
  • Skin biopsy—may help establish diagnosis before death of the pet; diagnosis must be confirmed by identification of rabies virus infection from central nervous system tissue

Follow-Up Care

Patient Monitoring

  • All suspected rabies patients should be isolated securely and monitored for any development of mood change, attitude change, or clinical signs that might suggest the diagnosis.
  • An apparently healthy dog or cat that bites or scratches a person should be monitored for a period of 10 days or according to local or state regulations; if no signs of illness occur in the pet within 10 days, the person has had no exposure to the virus; dogs and cats do not shed the virus for more than 3 days before development of clinical disease.
  • An unvaccinated dog or cat that is bitten or exposed to a known rabid animal must be quarantined for up to 6 months or according to local or state regulations.

Preventions and Avoidance

  • Vaccines (dogs and cats)—vaccinate according to standard recommendations and state and local requirements; all dogs and cats with any potential exposure to wildlife or other dogs and cats; vaccinate after 12 weeks of age; then 12 months later; then every 3 years using a vaccine approved for 3 years’ duration; use only inactivated virus or recombinant vector vaccines for cats.
  • Rabies-free countries—entering dogs and cats are quarantined for long periods, usually 6 months.
  • Disinfection—any contaminated area, cage/run, food dish, water bowl or instruments must be disinfected thoroughly; use a 1:32 dilution (4 ounces per gallon) of household bleach to inactivate the virus quickly.

Possible Complications

  • Paralysis
  • Attitude or behavior changes
  • Death
  • Exposure of rabies virus to other animals or people

Expected Course and Prognosis

  • Prognosis—grave; almost invariably fatal
  • Dogs and cats with clinical infection usually succumb within 1–10 days of onset of clinical signs; often within 3–4 days

Key Points

  • Rabies is a serious, usually fatal infection for the pet; rabies can be spread from animals to people (known as having “zoonotic potential”).
  • Tell your veterinarian about any possible human exposure (such as contact with the pet or other suspected rabid animal or a bite or scratch).
  • Any person possibly exposed to rabies should see a physician immediately.
  • Local public health officials must be notified.

Pemphigus

Pemphigus

BASICS-Overview

  • A group of diseases in which the immune system attacks the skin (known as “auto-immune dermatoses”); auto-immune diseases are ones in which the body produces antibodies against its own tissue; an “antibody” is a protein that is produced by the immune system in response to a specific antigen (a substance that induces an immune response)—when the body is exposed to the antigen (in the case of pemphigus, the antigen is some part of the skin), the antibody responds, resulting in signs of disease.
  • The pemphigus group of diseases is characterized by varying degrees of loss of tissue on the surface of the skin, frequently with inflammation (known as “ulceration”); dried discharge on the surface of a skin lesion (known as a “crust”); and formation of small, raised skin lesions containing pus (known as “pustules”) and blisters or small, circumscribed elevation of the outer layer of the skin filled with clear fluid (known as “vesicles”)
  • Affects the skin and sometimes the moist tissues of the body (known as “mucous membranes”)
  • Forms identified in animals include pemphigus foliaceous, pemphigus erythematosus, pemphigus vulgaris, panepidermal pustular pemphigus/vegetans, canine benign familial chronic pemphigus (Hailey-Hailey disease), and paraneoplastic pemphigus; type of pemphigus based on location of skin lesions and microscopic appearance of skin lesions

Genetics

  • Benign familial chronic pemphigus (Hailey-Hailey disease)—may be a genetic disease

Signalment/Description of Pet

Species

  • Pemphigus foliaceus, erythematosus, and vulgaris—dogs and cats
  • Panepidermal pustular pemphigus—dogs

Breed Predilections

  • Pemphigus foliaceus—Akitas, bearded collies, chow chows, dachshunds, Doberman pinschers, Finnish spitzes, Newfoundlands, and schipperkes
  • Pemphigus erythematosus—collies, German shepherd dogs, and Shetland sheepdogs

Signs/Observed Changes in the Pet

Pemphigus Foliaceus

  • Scales (accumulations of surface skin cells, such as seen in dandruff); crusts (dried discharge on the surface of skin lesions); pustules (raised skin lesions containing pus); superficial loss of skin tissue (known as “erosions”); reddened skin (known as “erythema”); hair loss (known as “alopecia”); circular patterns of hair loss (alopecia) bordered by scales or surface peeling of the skin (pattern is known as an “epidermal collarette”); and thickening of the skin (known as “hyperkeratosis”) of the footpads with furrows or slits (known as “fissures”)
  • Occasional blisters (vesicles) are transient
  • Common involvement—head, ears, and footpads; often becomes generalized
  • Lesions involving the moist tissues of the body (mucous membranes) and areas where the moist tissues of the body contact the skin, such as the lips (areas known as “mucocutaneous junctions”) are uncommon
  • Cats—nipple and nailbed involvement are common
  • Sometimes enlarged lymph nodes (known as “lymphadenopathy”), fluid buildup in the skin (known as “edema”), depression, fever, and lameness (if footpads involved) may be present; however, pets are often in good health
  • Variable pain and itchiness (known as “pruritus”)
  • Secondary bacterial infection is possible

Pemphigus Erythematosus

  • Same signs as for pemphigus foliaceus
  • Lesions usually confined to head, face, and footpads
  • Loss of pigment of the moist tissues (mucous membranes) and skin (known as “mucocutaneous depigmentation”) more common than with other forms of pemphigus; loss of pigment may precede crusting

Pemphigus Vulgaris

  • Pemphigus; loss of pigment may precede crusting
  • Ulcers of the mouth are frequent, and may precede skin lesions
  • Ulcerative lesions; superficial loss of skin tissue (erosions); circular patterns of hair loss (alopecia) bordered by scales or surface peeling of the skin (pattern is called epidermal collarettes), blisters, and crusts (dried discharge on the surface of skin lesions)
  • More severe than pemphigus foliaceus and pemphigus erythematosus
  • Affects moist tissues of the body (mucous membranes), areas where the moist tissues of the body contact the skin, such as the lips (mucocutaneous junctions), and skin; may become generalized
  • Area under the front legs and between the rear legs (known as the “axillae and groin”) often involved
  • Positive Nikolsky sign (new or extended erosive lesion created when lateral pressure is applied to the skin near an existing lesion)
  • Variable itchiness (pruritus) and pain
  • Lack of appetite (known as “anorexia”), depression, and fever
  • Secondary bacterial infections are common

Panepidermal Pustular Pemphigus

  • Pustule (raised skin lesion containing pus) groups become masses that ooze
  • Involvement of the mouth has not been seen
  • No systemic illness

Causes

  • Undetermined—genetics and a possible triggering event (such as a viral infection or medication)

Risk Factors

  • Undetermined

Treatment

Health Care

  • Initial inpatient supportive therapy for severely affected pets
  • Outpatient treatment with initial frequent hospital visits (every 1–3 weeks); taper to every 1–3 months when remission is achieved and the pet is on a maintenance medical regimen
  • Severely affected pets may require antibiotics and hydrotherapy/soaks

Diet

  • Low-fat—to avoid inflammation of the pancreas (known as “pancreatitis”), which can be a side effect of steroids and (possibly) azathioprine therapy

Surgery

  • Surgical biopsy of the skin lesion and the skin surrounding the lesions

Medications

Medications presented in this section are intended to provide general information about possible treatment. The treatment for a particular condition may evolve as medical advances are made; therefore, the medications should not be considered as all inclusive

Pemphigus Foliaceus and Pemphigus Vulgaris

  • Steroids—prednisone or prednisolone
  • Chemotherapeutic drugs and other drugs to decrease the immune response—more than half of pets require medications other than steroids to decrease the immune response; these drugs generally work in conjunction with prednisone, allowing reduction in dose and side effects of the steroid; examples include azathioprine, chlorambucil, cyclophosphamide, cyclosporine, and dapsone
  • Gold-salt treatment or chrysotherapy—gold salts are used to decrease inflammation and the immune response; often used in conjunction with prednisone; such as auranofin

Pemphigus Erythematosus and Panepidermal Pustular Pemphigus

  • Steroids—prednisone or prednisolone administered by mouth
  • Steroids administered by application directly to the skin (known as “topical steroids) may be sufficient in mild cases

Alternative Steroids

  • Use instead of prednisone, if undesirable side effects to prednisone or poor response occur
  • Methylprednisolone—for pets that tolerate prednisone poorly
  • Triamcinolone
  • Steroid pulse therapy—methylprednisolone sodium succinate administered intravenously for 3 consecutive days to induce remission; limited application

Topical Steroids (Administered to the Skin Directly)

  • Hydrocortisone cream
  • More potent topical steroids—0.1% betamethasone, fluocinolone, or 0.1% triamcinonide

Miscellaneous Medications

  • Tetracycline and niacinamide

Follow-Up Care

  • Monitor response to therapy

Monitor for medication side effects—routine bloodwork (complete blood count [CBC] and serum biochemistry), especially pets on high doses of steroids, chemotherapeutic drugs, or gold-salt treatment; check every 1–3 weeks, then every 1–3 months when in remission

Prevention and Avoidance

  • Pet should avoid the sun, because ultraviolet (UV) light may worsen the lesions

Possible Complications

  • Depend on type of pemphigus
  • Secondary infections
  • Side effects of medications may affect quality of life
  • Pemphigus foliaceus and pemphigus vulgaris may be fatal, if untreated (especially pemphigus vulgaris)

Expected Course and Prognosis

  • Treatment with steroids and chemotherapeutic drugs and medications to decrease the immune response is needed
  • Pets may require medication for life
  • Monitoring is necessary
  • Side effects of medications may affect quality of life
  • May be fatal, if untreated (especially pemphigus vulgaris)
  • Secondary infections cause morbidity and possible mortality (especially pemphigus vulgaris)

Pemphigus Erythematosus and Panepidermal Pustular Pemphigus

  • Relatively benign and self-limiting
  • Steroids administered by mouth eventually may be tapered to low maintenance doses; may be stopped in some pets (as directed by your pet’s veterinarian)
  • Skin disorder (known as “dermatosis”) develops, if untreated; generalized (systemic) signs are rare
  • Prognosis fair

Key Points

  • A group of diseases in which the immune system attacks the skin (known as “auto-immune dermatoses”)
  • Pet should avoid the sun, because ultraviolet (UV) light may worsen lesions

Lyme Disease

Lyme Disease – An Overview

  • One of the most common tick-transmitted diseases in the world.
  • Caused by spirochete species of the Borrelia burgdorferi group (such as B. burgdorferi, B. afzelii, B. garinii).
  • Dominant clinical feature (dogs)—recurrent lameness due to inflammation of the joints (known as “arthritis”); sometimes lack of appetite (known as “anorexia”) and depression; may develop kidney and rarely heart or nervous system disease.
  • Reported in people, dogs, horses, and occasionally in cats.
  • Also known as “Lyme borreliosis” or “borreliosis”.
  • Experimentally, young dogs (puppies) appear to be more susceptible to disease than do adult dogs

Genetics

  • Certain dog breeds (such as the Bernese mountain dog) are reported to develop severe kidney failure following infection with Borrelia.

Signs/Observed Changes in the Pet

  • Recurrent lameness due to inflammation of the joints (arthritis).
  • In studies, sudden (acute) form lasts for only 3–4 days; recurs days to weeks later in the same or in other legs (known as “shifting-leg lameness,” characterized by lameness in one leg, then that leg appears to be normal and another leg is involved); one or more joints may be swollen and warm; a pain response is elicited by feeling the joint; responds well to antibiotic treatment.
  • Affected dogs may refuse to walk or stand or may walk stiffly, with an arched back, and be sensitive to touch.
  • Long-term (chronic) inflammation of several joints, in which the bones around the joints are not destroyed (known as “non-erosive polyarthritis”) is found in pets with prolonged infection without adequate treatment; may persist despite antibiotic therapy.
  • Fever, lack of appetite (anorexia) and depression may accompany inflammation of the joints (arthritis).
  • Superficial lymph nodes close to the site of the infecting tick bite may be swollen.
  • Kidneys—reported glomerulonephritis with immune-complex deposition in the glomeruli leading to fatal kidney disease; “glomerulonephritis” is inflammation and accompanying dysfunction of glomeruli (plural of glomerulus) of the kidney; each kidney is composed of thousands of nephrons (the functional units of the kidney, each consisting of the glomerulus [a tuft of blood capillaries—the “blood filter”] and a series of tubes and ducts, through which the filtered fluid flows, as urine is produced); inflammation most commonly is due to the presence of immune complexes in the glomerulus.
  • Kidneys—loss of protein through the kidneys (condition known as “protein-losing nephropathy”) with resulting low levels of albumin (the type of protein lost through the kidneys) in the blood (condition known as “hypoalbuminemia”).
  • Kidney failure (signs include vomiting; diarrhea; lack of appetite [anorexia]; weight loss; increased urination [known as “polyuria”] and increased thirst [known as “polydipsia”]; fluid buildup in the tissues, especially the legs and under the skin [known as “peripheral edema”] or fluid buildup in the abdomen [known as “ascites”]).
  • Heart abnormalities—reported, but rare; include complete heart block.
  • Nervous system complications—rare.

Causes

  • Borrelia burgdorferi—transmitted by slow-feeding, hard-shelled tick species of the genus Ixodes (such as Ixodes scapularis [the deer tick], Ixodes pacificus, Ixodes ricinus, Ixodes persulcatus).
  • Infection—only after a tick (nymph or adult female) carrying Borrelia has been attached to the host for at least 18 hours.

Risk Factors

  • Roaming in tick-infested environment, where Lyme borreliosis is common (known as an “endemic area”)

Treatment for Lyme Disease

  • Outpatient
  • Keep pet warm and dry

Activity

  • Reduced activity advisable until clinical signs improve

Diet

  • No change needed

Surgery

  • Tapping the joint and removing joint fluid (known as “aspiration of synovial fluid”) may be considered for diagnostic purposes

Medications

Medications presented in this section are intended to provide general information about possible treatment. The treatment for a particular condition may evolve as medical advances are made; therefore, the medications should not be considered as all inclusive:

  • Most commonly used antibiotics—doxycycline, amoxicillin, or azithromycin.
  • Doxycycline—preferred in pets that have both Borrelia and Anaplasma phagocytophilum infections at the same time (Anaplasma is another tick-borne agent that causes disease).
  • Antibiotics do not eliminate the infection; consequently, persistent infection with a very low bacterial burden remains; treatment significantly improves clinical signs and disease.
  • Recommended treatment period—4 weeks.
  • Steroids—initially may cause signs to improve; may cover up or mask effects of antibiotics for diagnostic purposes; may increase clinical signs later by decreasing the ability of the pet to develop a normal immune response (known as “immunosuppression”).
  • Nonsteroidal pain medications—use judiciously to avoid covering up or masking signs; use only as directed by your pet’s veterinarian.

Follow-Up Care

Patient Monitoring

  • Improvement in sudden (acute) inflammation of the joints caused by Borrelia (known as “Lyme arthritis”) should be seen within 2–5 days of antibiotic treatment.
  • If no improvement within 2–5 days or is signs worsen, consider a different diagnosis.

Preventions and Avoidance

  • Mechanical removal of ticks—groom pets daily; discuss appropriate technique for removing ticks from your pet with the veterinarian.
  • Prevention of tick attachment—products to kill ticks (known as “acaricides”) and tick repellents are available commercially as spot-on topical products, sprays or collars; any such product should be used only according to label directions (do not use permethrin on cats).
  • Vaccines—are available commercially for dogs; talk to your pet’s veterinarian about the vaccine and vaccination protocols.
  • Tick population control in the environment—restricted to small areas; limited success by reducing deer and/or rodent population.

Possible Complications

  • Fatal kidney failure
  • Heart block
  • Central nervous system disorders

Expected Course and Prognosis

  • Recovery from sudden (acute) lameness expected 2–5 days after initiation of antibiotic treatment.
  • Disease may be recurrent with intervals of weeks to months; responds again to antibiotic treatment.

Key Points

  • Treatment of Lyme disease requires regular administration of antibiotics as prescribed by your pet’s veterinarian.
  • Prevent tick attachment—products to kill ticks (acaricides) and tick repellents are available commercially; any such product should be used only according to label directions (do not use permethrin on cats).
  • Diagnosis of Lyme disease (Lyme borreliosis) in a pet increases the risk to people living in the same area, as the people may be infected with Borreliaif they come into contact with ticks in the environment; they too should prevent tick attachment to themselves and should inform their personal physician of the pet’s diagnosis if they become ill.