Bacterial Pneumonia

Bacterial Pneumonia – An Overview

  • Inflammation in the lung as a response to disease-causing bacteria, characterized by accumulation of inflammatory cells and fluid in the lung, conducting airways (bronchi and bronchioles), and alveoli (the terminal portion of the airways, in which oxygen and carbon dioxide are exchanged).
  • “Pneumonia” is inflammation of the lungs.
  • “Broncho” refers to the bronchi, the airways leading from the windpipe (known as the “trachea”) into the lungs.
  • “Upper respiratory tract” (also known as the “upper airways”) includes the nose, nasal passages, throat (pharynx), and windpipe (trachea).
  • “Lower respiratory tract” (also known as the “lower airways”) includes the bronchi, bronchioles, and alveoli (the terminal portion of the airways, in which oxygen and carbon dioxide are exchanged).
  • Inherited inflammation of the nose and inflammation of the smaller bronchi and lungs (known as rhinitis-bronchopneumonia complex”)—Irish wolfhound.
  • Dogs can get pneumonia, less common in cats

Breed Predilections

  • Dogs—sporting breeds, hounds, working breeds, and mixed-breed dogs (greater than 12 kg [26 lbs] of body weight)

Mean Age and Range

  • Dogs—common in young and old dogs; range, 1 month–15 years; many cases in puppies less than 1 year of age

Risk Factors

  • Contact of animals that have not been vaccinated or have not responded to vaccinations with animals that are infected with canine distemper virus (dogs or wild carnivores)

Signs/Observed Changes in the Pet

  • Cough
  • Fever
  • Labored breathing
  • Exercise intolerance
  • Lack of appetite (known as “anorexia”) and weight loss
  • Sluggishness (lethargy)
  • Nasal discharge
  • Difficult or rapid breathing
  • Abnormal breath sounds on listening to the lungs with a stethoscope (known as “auscultation”)—increased intensity or breath sounds over the bronchi; short, rough snapping sounds (known as “crackles”); and squeaking or whistling sounds (known as “wheezes”)
  • Dehydration

Causes

Dogs

  • Most common primary disease-causing organisms of the respiratory tract— Bordetella bronchiseptica and Mycoplasma.
  • Most common gram-positive bacteria—Staphylococcus, Streptococcus, and Enterococcus; gram staining is a technique in which slides with potential bacteria on them are stained in a sequential manner; gram-positive bacteria stain dark purple while gram-negative bacteria stain pink; gram staining allows differentiation of bacteria into groups (that is, gram-positive or gram-negative).
  • Most common gram-negative bacteria— Escherichia coli, Klebsiella, Pseudomonas, Pasteurella
  • Anaerobic bacteria (bacteria that can live and grow in the absence of oxygen)—found in lung abscesses and various types of pneumonia (particularly with aspiration or foreign bodies); approximately 20% of pets with bacterial pneumonia have anaerobic bacterial infections.

Cats

  • Bacteria—Bordetella bronchiseptica, Pasteurella, and Moraxella most frequently reported; Mycoplasma considered a primary disease-causing microorganism (known as a “pathogen”) in the lower respiratory tract.
  • Carrier state—may exist; periods of shedding Bordetella bronchiseptica after stress; infected female cats (queens) may not shed the organism during pregnancy (prepartum) but begin shedding it after delivering the kittens (postpartum), serving as a source of infection for kittens.

Risk Factors

  • Preexisting viral infection.
  • Regurgitation (return of food or other contents from the esophagus or stomach back up through the mouth), dysphagia (difficulty swallowing), or vomiting (forceful ejection of stomach contents up through the esophagus and mouth).
  • Functional or structural (anatomic) defects—paralysis of the voice box or larynx (known as “laryngeal paralysis”); enlarged esophagus (known as “megaesophagus”); cleft palate; inherited disorder in which the normal secretion clearance mechanism of the lungs is defective (known as “primary ciliary dyskinesia”).
  • Reduced level of consciousness—stupor, coma, or anesthesia.
  • Foreign body in the bronchi (part of the airway).
  • Long-term (chronic) dilation of bronchi or bronchioles, as a consequence of inflammation or blockage of the airway (known as “bronchiectasis”).
  • Drugs to decrease the immune response (known as “immunosuppressive drugs”)—such as chemotherapeutic drugs and steroids.
  • Severe metabolic disorders—excess levels of urea and other nitrogenous waste products in the blood (known as “uremia” or “azotemia”); sugar diabetes (diabetes mellitus); excessive production of steroids by the adrenal glands (known as “hyperadrenocorticism” or “Cushing’s syndrome”).
  • Presence of pus-forming bacteria and their poisons in the blood or tissues (known as “sepsis”).
  • Age—very young more susceptible to fatal infections.
  • Vaccination status.
  • Environment—housing, sanitation, ventilation.
  • Abnormal function of cells that normally remove bacteria and foreign materials from the body (known as “phagocyte dysfunction”)—feline leukemia virus (FeLV) infection and diabetes mellitus.
  • Complement (a protein substance in the blood that contributes to the destruction and removal of bacteria from the body) deficiency—rare.
  • Selective immunoglobulin A (IgA) deficiency; immunoglobulin A is an immune protein, found in the intestines; it functions as a protective barrier to prevent limit antigens (substance to which the immune system is responding and producing antibodies) and disease-causing microorganisms from entering the body through the intestines—rare.
  • Combined T-cell and B-cell dysfunction—rare; a lymphocyte is a type of white blood cell, formed in lymphatic tissue throughout the body; lymphocytes are further divided into T lymphocytes (which are involved in cell-mediated immunity), so-called “T-cells” and B lymphocytes (which produce antibodies as part of the immune process), so-called “B-cells”—rare.

Treatment

Health Care

  • Inpatient—recommended with signs involving multiple body systems (such as lack of appetite [anorexia], high fever, weight loss, and sluggishness [lethargy]).
  • Maintain normal hydration—important to aid the normal secretion clearance mechanism of the lungs; use a balanced electrolyte solution.
  • Administration of medication in a fine spray (known as “nebulization”) with saline aerosol—results in more rapid resolution, if used with physiotherapy and antibiotics.
  • Physiotherapy—efforts to dislodge secretions in the lungs and to induce coughing (known as “coupage”); windpipe manipulation to stimulate mild cough; and postural drainage; may enhance clearance of secretions; always do immediately after nebulization; avoid allowing the pet to lie in one position for a prolonged time.
  • Oxygen therapy—for pets with low levels of oxygen in their blood (known as “hypoxemia”) and signs of severe breathing difficulties (known as “respiratory distress”).

Activity

  • Restrict during treatment (inpatient or outpatient), except as part of physiotherapy after administration of medication in a fine spray (nebulization).

Diet

  • Ensure normal intake of food, with foods high in protein and calorie or energy density.
  • Feeding directly into the intestinal tract (known as “enteral feeding”) or through the veins (known as “parenteral nutrition”)—indicated in severely ill pets.
  • Use caution in feeding pets with an enlarged esophagus (megaesophagus); lack of normal function of the voice box or larynx (known as “laryngeal dysfunction”) or surgery on the voice box or larynx; disease of the throat or pharynx (known as “pharyngeal disease”), and pets that are unable to get up (they are recumbent).

Surgery

  • Surgical removal of a lung lobe (known as “lung lobectomy”)—may be indicated with lung abscesses or foreign body in the bronchus with secondary pneumonia; may be indicated if the pet is unresponsive to conventional treatment and disease is limited to one or two lobes of the lung(s).

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

  • Antibiotics are best selected based on results of bacterial culture and susceptibility testing from transtracheal wash (a technique in which samples from the lower airways are obtained for bacterial culture and/or for evaluation through a microscope) or other diagnostic techniques.
  • Reasonable initial antibiotic choices pending culture results include amoxicillin–clavulanic acid, cephalexin, enrofloxacin, or trimethoprim-sulfonamide.
  • Gram-positive cocci—ampicillin, ampicillin-sulbactam; amoxicillin; amoxicillin–clavulanic acid; azithromycin; chloramphenicol, erythromycin; gentamicin; trimethoprim-sulfonamide; first-generation cephalosporins.
  • Gram-negative rods—enrofloxacin; chloramphenicol; gentamicin; trimethoprim-sulfonamide; amikacin; marbofloxacin; carboxypenicillins.
  • Bordetella—doxycycline; chloramphenicol; enrofloxacin; azithromycin.
  • Mycoplasma—doxycycline, enrofloxacin, marbofloxacin, chloramphenicol.
  • Anaerobes (bacteria that can live and grow in the absence of oxygen)—amoxicillin–clavulanic acid; chloramphenicol; metronidazole; clindamycin; ticarcillin-clavulanic acid.
  • Administration of gentamicin in a fine spray (known as “gentamicin nebulization”) for Bordetella—typically used in conjunction with antibiotics given by mouth or injection.
  • Continue treatment for at least 10 days beyond clinical resolution and/or 1–2 weeks following resolution of x-ray (radiograph) evidence of pneumonia.

Antibiotics

  • Recommended by some veterinarians; no objective evidence that they increase movement of mucus or mobilization of secretions.

Bronchodilators

  • Recommended by some veterinarians; used to decrease spasm of the bronchi; bronchodilators are medications that enlarge the bronchi and bronchioles in the lungs.

Follow-Up Care

Patient Monitoring

  • Monitor breathing rate and effort.
  • Complete blood count (CBC) should be performed periodically; CBC should return to normal as the pet responds to treatment.
  • Arterial blood gases, to monitor levels of oxygen and carbon dioxide in the blood—most sensitive monitor of progress.
  • Monitor pulse oximetry; : “pulse oximetry” is a means of measuring oxygen levels in blood.
  • Listen to the pet’s lungs (auscultate) frequently.
  • Chest x-rays (radiographs)—improve more slowly than the clinical signs.

Preventions and Avoidance

  • Vaccination—against upper respiratory viruses; against Bordetella bronchiseptica, if dog is boarded or exposed to large number of other dogs.
  • Catteries—environmental strategies to lower the number of cats or the close proximity in which they are housed (known as “population density”) and improve hygiene help control outbreaks of bordetellosis (infection caused by Bordetella).

Possible Complications

  • Presence of pus-forming bacteria and their poisons in the blood or tissues (sepsis).

Expected Course and Prognosis

  • Prognosis—good with aggressive anti-bacterial and supportive therapy; more guarded in young pets, pets with decreased ability to develop a normal immune response (immunodeficiency), and pets that are debilitated or have severe underlying disease.
  • Prolonged infection—potential for long-term (chronic) inflammation of the bronchi (bronchitis) or chronic dilation of bronchi or bronchioles, as a consequence of inflammation or blockage of the airway (bronchiectasis) in any pet.
  • High death rates are associated with severely low levels of oxygen in the blood (hypoxemia) and presence of pus-forming bacteria and their poisons in the blood or tissues (sepsis).

Key Points

  • Inflammation in the lung as a response to disease-causing bacteria, characterized by accumulation of inflammatory cells and fluid in the lung, conducting airways (bronchi and bronchioles), and alveoli (the terminal portion of the airways, in which oxygen and carbon dioxide are exchanged).
  • More common in dogs than in cats.
  • Antibiotics are best selected based on results of bacterial culture and susceptibility testing.
  • High death rates are associated with severely low levels of oxygen in the blood (hypoxemia) and presence of pus-forming bacteria and their poisons in the blood or tissues (sepsis).

Emergency Care

Your Plan Should Include All Family Members

The best way to protect your household from the effects of a disaster is to have a disaster plan. If you are a pet owner, that plan must include your pets. Being prepared can save their lives.

Different disasters require different responses. But whether the disaster is a hurricane or a hazardous spill, you may have to evacute your home.

In the event of a disaster, if you must evacuate, the most important thing you can do to protect your pets is to evacuate them too. If it’s not safe for you to stay behind then it’s not safe to leave pets behind either. Take action now so you know how to best care for your furry friends when the unexpectecd occurs.

Know a Safe Place to Take Your Pets

  • Local and state health and safety regulations do no permit the Red Cross to allow pets in disaster shelters. (Service animals are allowed in Red Cross shelters.)
  • Contact hotels and motels outside your local area to check their policies on accepting pets and restrictions on number, size and specicies. Ask if “no pet” policies can be waived in an emergency. Keep a list of “pet friendly” places, including phone numbers, with your disaster supplies.
  • Ask friends, relativies or others outside the affected area whether they could shelter your animals.
  • Make a list of boarding facilities and veterinarians who could shelter animals in an emergency; include 24-hour phone numbers.
  • Ask local animal shelters if they provide emergency shleter or foster care for pets during a disaster.

Assemble a Pet Emergency Preparedness Kit

Keep your pet’s ssential supplies in sturdy containers that can be easily accessed and carried (a duffle bag or covered trash containers, for exmpale). Your pet emergency preparedness kit should include:

  • Medications and medical records (stored in a waterproof container) and a First Aid kit.
  • Sturdy leashes, harness, and/or carriers to transport pets safely and ensure that your animals can’t escape.
  • Current photos of your pets in case they get lost.
  • Food, drinkable water, bowls, cat litter/pan, and manual can opener.
  • Information on feeding schedules, medical conditions, behavior problems, and the name and number of your veterinarian in case you have to foster or board your pets.
  • Pet bed or toys if easily transportable.

Help Emergency Workers Help Your Pets

The ASPCA recommends using a rescue sticker alert to let people know that pets are isnide your home. Make sure it is visible to rescue worker, and that it includes the types and number of pets in your household and your veterinarian’s phone number.

If you must evacuate with your pets (and if time allows) write “EVACUATED” aross the stickers so rescue workers don’t waste time looking for them.

Skin Ulcers

Ulcers of the Skin – An Overview

  • Erosions are shallow defects in the skin, which only affect the skin’s upper layers; erosions can be quite painful, but tend to heal quickly if protected (and the underlying cause is eliminated)
  • Ulcers are deeper defects in the skin, where the surface layers are compromised completely; ulcers require careful wound care to prevent infection, and tend to heal slowly
  • Erosive or ulcerative dermatoses are a group of dissimilar skin disorders, characterized by the presence of erosions or ulcers

Genetics

  • Some diseases characterized by erosions or ulcers of the skin are likely inherited since they tend to occur in certain breeds; however, no genetic screening tests are available

Signalment/Description of Pet

Species

  • Dogs
  • Cats

Signs/Observed Changes in the Pet

  • Depend on cause
  • Erosions or ulcers; they may be found anywhere on the body
  • Hair loss (known as “alopecia”)
  • Single or multiple lesions; lesions may be inflamed (indicated by redness)
  • May see lesions over pressure points (such as skin over bones)
  • May have dried discharge on the surface of a skin lesion (known as a “crust”) or may have moist discharge
  • May have loss of pigment of skin and/or hair (known as “depigmentation”)

Causes

  • Wide variety of diseases may result in erosions or ulcers of the skin; common causes are burns, trauma, and skin infections; more complicated diseases, such as drug reactions, certain types of cancers, auto-immune diseases of the skin, and viruses also may cause erosions or ulcers that appear identical to burns or trauma—your pet’s veterinarian may need to run a battery of tests (including bloodwork, cultures for different types of infections, and skin biopsies) to identify the cause and prescribe proper treatment
  • In some cases, an underlying cause cannot be identified and the cause is “unknown,” so-called “idiopathic” disorder or disease
  • Disorders that cause erosions or ulcers of the skin include the following (a partial list):
  • Immune-Mediated Disorders
  • Inflammation of blood vessels (known as “vasculitis”)
  • Canine juvenile cellulitis (puppy strangles)
  • Toxic epidermal necrolysis (usually medication-induced)
  • Feline indolent ulcer (rodent ulcer)
  • Auto-immune disorders (such as pemphigus or lupus) in which the immune system attacks the skin
  • Infectious Disorders
  • Skin infection characterized by the presence of pus (known as “pyoderma”) caused by Staphylococcus
  • Deep fungal or mycotic infections (such as sporotrichosis, cryptococcosis, histoplasmosis)
  • Superficial fungal infections (Malassezia dermatitis, dermatophytosis)
  • Actinomycetic bacteria (such as Nocardia, Actinomyces, Streptomyces)
  • Feline cow pox
  • Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) related disease
  • Parasitic Disorders
  • Demodectic mange (demodicosis)
  • Sarcoptic or notoedric mange
  • Flea-bite allergy
  • Congenital/Hereditary Disorders
  • Various skin disorders in which the skin is abnormal at birth (that is, a “congenital” abnormality) that may or may not be inherited
  • Metabolic Disorders
  • Liver disease
  • Excessive production of steroids by the adrenal glands (known as “hyperadrenocorticism” or “Cushing’s syndrome”), especially when complicated by secondary infections or calcium deposits in the skin (known as “calcinosis cutis”
  • Cancer
  • Squamous cell carcinoma
  • Mast cell tumors
  • Lymphoma of the skin (“mycosis fungoides”)
  • Nutritional Disorder
  • Zinc-responsive dermatosis
  • Generic dog-food dermatosis
  • Miscellaneous
  • Thermal, electrical, solar, or chemical burns
  • Frost bite
  • Chemical irritants
  • Venomous snake and insect bites

Risk Factors

  • Depend on underlying cause

Treatment

Health Care

  • Outpatient for most diseases
  • Varies widely according to the cause
  • Keeping eroded or ulcerated skin clean and protected are key to healing; if the cause is known, specific drug therapies may be prescribed
  • Pain management may be necessary for some pets, based on cause of condition
  • Your veterinarian will tailor a management program that is best for your pet’s individual case
  • Hydrotherapy, which may be achieved with either a whirlpool bath or by spraying cool water under pressure against the ulcerated skin can be helpful in many cases; ask your pet’s veterinarian first to be sure that hydrotherapy is appropriate for your pet’s condition
  • Avoid the temptation to apply “over-the-counter” creams and ointments to erosions and ulcers, without first checking with your veterinarian—some commonly used products (such as those containing neomycin) actually may delay healing in some cases; other products may contain types of alcohol or other ingredients that could cause pain upon application

Diet

  • Supportive therapy with fluid and nutritional supplementation is indicated in cases with severe fluid and protein loss through the damaged skin
  • Good quality diet
  • Supplementation of zinc in the diet for pets with zinc-responsive skin conditions

Surgery

  • Skin biopsy may be necessary for diagnosis

Medications

Vary widely according to cause.

Follow-Up Care

Patient Monitoring

  • Case-by-case basis, depending on the disease process, presence of generalized (systemic) disease(s), medications used, and potential side effects expected
  • Follow-up care is important, especially for slowly healing ulcers; a veterinarian should check progress of the wound at least every other week to be sure that healing is proceeding properly and that infection has not complicated the healing process

Possible Complications

  • Depend on cause
  • Some diseases are potentially life-threatening
  • Some diseases are caused by agents that may be spread to people (known as having “zoonotic potential”)
  • Superinfections and drug side effects are possible in cases requiring medications to decrease the body’s immune response (known as “immunosuppression”)
  • Some infectious diseases (such as nocardiosis, atypical mycobacteriosis) may be controlled, but not cured

Expected Course and Prognosis

  • Vary widely according to cause

Key Points

  • Wide variety of diseases may result in erosions or ulcers of the skin; common causes are burns, trauma, and skin infections; more complicated diseases, such as drug reactions, certain types of cancers, auto-immune diseases of the skin, and viruses also may cause erosions or ulcers that appear identical to burns or trauma—your pet’s veterinarian may need to run a battery of tests (including bloodwork, cultures for different types of infections, and skin biopsies) to identify the cause and prescribe proper treatment
  • Follow-up care is important, especially for slowly healing ulcers; a veterinarian should check progress of the wound at least every other week to be sure that healing is proceeding properly and that infection has not complicated the healing process

Skin Inflammation

Inflammation of the Skin and Muscles (Dermatomyositis) – An Overview

  • “Dermatomyositis” is an inherited inflammatory disease of the skin, muscles, and blood vessels that develops in young collies, Shetland sheepdogs, and their crossbreeds

Genetics

  • Collies and Shetland sheepdogs—inherited as an autosomal dominant trait, with variable expression

Signalment/Description of Pet

Species

  • Dogs

Breed Predilections

  • Collies, Shetland sheepdogs, and their crossbreeds
  • Similar signs have been reported in other breeds, such as the Beauceron shepherd, Welsh corgi, Lakeland terrier, chow chow, German shepherd dog, and Kuvasz
  • Some dogs in other breeds with similar signs are now classified as having “ischemic dermatopathy” (dermatomyositis-like skin disease) and not “dermatomyositis” as previously reported

Mean Age and Range

  • Skin lesions typically develop before six months of age, and may develop as early as 7 weeks of age
  • The full extent of lesions usually is present by 1 year of age, and may lessen thereafter
  • Adult-onset dermatomyositis can occur, but is rare

Signs/Observed Changes in the Pet

  • Clinical signs vary from subtle skin lesions and inflammation of muscles that is does not cause clinical signs (known as “subclinical myositis”) to severe skin lesions and a generalized decrease in muscle mass (known as “muscle atrophy”) with an abnormal gait, and an enlarged esophagus (part of the digestive tract, the tube running from the throat to the stomach; condition known as “megaesophagus”)
  • Skin lesions around the eyes, lips, face, inner surface of the prick ears, tip of the tail, and bony prominences vary in intensity; the entire face may be involved—skin lesions may increase and decrease over time (known as a “waxing and waning” course); signs usually seen in affected dogs before they are 6 months of age
  • Skin lesions—characterized by variable degrees of crusted areas with loss of the top surface of the skin (known as “erosions” or “ ulcers” based on depth of tissue loss) and hair loss (known as “alopecia”), with reddening of the skin (known as “erythema”), accumulations of surface skin cells, such as seen in dandruff (known as “scales”), and scars
  • Pressure points and exposed areas of skin over boney prominences commonly are affected first
  • Scars may occur as a sequela to initial skin lesions
  • More severely affected dogs may have difficulty eating, drinking, and swallowing
  • Stiff or high-stepping gait
  • Several litter mates may be affected, but the severity of the disease often varies significantly among affected dogs
  • Foot-pad ulcers and ulcers in the mouth, as well as nail abnormalities or loss, may occur
  • Inflammation of the muscles (myositis)—signs may be absent or vary from subtle decrease in the mass of the muscles extending from the top and side of the head, behind the eye, to the lower jaw (known as the “temporal muscles”) to generalized, symmetric loss of muscle mass (muscle atrophy) and stiff or high-stepping gait
  • Decrease in muscle mass (muscle atrophy) of the muscles extending from the bone below the eye to the lower jaw (known as the “masseter muscles”) that act to close the jaw and muscles extending from the top and side of the head, behind the eye, to the lower jaw (temporal muscles) that act to close the jaw—may be evident
  • Dogs with enlarged esophagus (megaesophagus) may present with aspiration pneumonia (inflammation of the lungs, caused by accidentally inhaling food, vomit, or liquids)

Causes

  • Hereditary in the collie, Shetland sheepdog, and their crosses
  • Infectious agents or medications may be triggering events
  • Immune-mediated disease in other dog breeds

Risk Factors

  • Mechanical pressure and trauma, and ultraviolet-light exposure may worsen skin lesions

Treatment

Health Care

  • Most dogs can be treated as outpatients
  • Dogs with severe inflammation of the muscles (myositis) and enlarged esophagus (megaesophagus) may need to be hospitalized for supportive care
  • Euthanasia may be indicated in severe cases

Activity

  • Avoid activities that may traumatize the skin
  • Keep indoors during the day to avoid exposure to intense sunlight

Diet

  • May need to change diet, if dog has enlarged esophagus (megaesophagus) or has difficulty eating and/or swallowing
  • Feed dog with food bowl elevated if enlarged esophagus (megaesophagus) develops
  • Assist dog with eating, if muscles involved with chewing are affected

Surgery

  • Skin biopsy—may be diagnostic for dermatomyositis, although this disease can be difficult to diagnose definitively
  • Muscle biopsy

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:

  • Non-specific symptomatic therapy includes hypoallergenic shampoo baths, treating secondary bacterial skin infections and Demodex mange (known as “demodicosis”), and avoiding trauma and sunlight
  • Vitamin E
  • Essential fatty acid supplements
  • Steroids (such as prednisone) to decrease inflammation
  • Nonsteroidal anti-inflammatory drugs (NSAIDs), as prescribed by your pet’s veterinarian
  • Pentoxifylline to improve blood flow and to reduce inflammation

Follow-Up Care

Preventions and Avoidance

  • Do not breed affected pets
  • Neuter intact pets to decrease the influence of hormones on clinical signs
  • Minimize trauma and exposure to sunlight

Possible Complicatoins

  • Secondary bacterial skin infection and Demodex mange (demodicosis)
  • Mildly to moderately affected dogs may have residual scarring
  • Severely affected dogs may have trouble chewing, drinking, and swallowing
  • Enlarged esophagus (megaesophagus) may develop, increasing the likelihood of aspiration pneumonia

Expected Course and Prognosis

  • The effectiveness of medical treatment can be difficult to assess because the disease tends to be cyclic in nature and often is self-limiting
  • Long-term prognosis—variable, depending on severity of disease
  • Minimal disease—prognosis good; tends to resolve spontaneously with no evidence of scarring
  • Mild to moderate disease—tends to resolve spontaneously, but residual scarring is common
  • Severe disease—prognosis for long-term survival is poor as the inflammation of the skin (known as “dermatitis”) and muscles (myositis) may be lifelong

Key Points

  • Dermatomyositis is considered an inherited disease in collies, Shetland sheepdogs, and their respective crosses
  • Affected dogs should not be used for breeding
  • The disease is not curable, although spontaneous resolution or waxing and waning of signs may occur

Pigment Loss

Loss of Pigment in Dogs & Cats

Overview

  • Disease or cosmetic condition involving loss of pigmentation of the skin and/or hair coat either by lack of pigmentation or by melanocyte damage; “melanocytes” are cells that produce pigment in the skin or hair
  • Normal pigment in the skin and hair coat is melanin
  • “Leukotrichia” is the medical term of whitening of the hair, without indication of location of the whitened hairs
  • “Poliosis” is the medical term of whitening of the hair on the head and/or face
  • “Leukoderma” is the medical term of whitening of the skin

Signalment/Description of Pet

Species

  • Dogs
  • Cats

Breed Predilections

  • Mucocutaneous pyoderma (bacterial skin infection involving areas of the lips, eyelids, nostrils)—German shepherd dogs
  • Systemic lupus erythematosus (auto-immune disease in which the body attacks its own skin and other organs) and discoid lupus erythematosus (auto-immune disease involving the skin only, usually the face)—collies, Shetland sheepdogs, German shepherd dogs
  • Pemphigus foliaceous (auto-immune disease involving the skin, characterized by inflammation with crusting and lesions containing pus)—chow chows, Akitas
  • Uveodermatologic syndrome (a rare syndrome in which the pet has inflammation in the front part of the eye, including the iris [condition known as “anterior uveitis”] and coexistent inflammation of the skin [known as “dermatitis”], characterized by loss of pigment in the skin of the nose and lips)—Akitas, Samoyeds, Siberian huskies
  • Vitiligo (condition characterized by symmetrical lack of pigment in the skin and white hair coat, especially involving the face and nose) in dogs—Belgian Tervuren, German shepherd dogs, Doberman pinschers, rottweilers, German shorthaired pointer, Old English sheepdog, and dachshund
  • Seasonal nasal hypopigmentation (loss of pigment in the tough, hairless skin of the nose [known as the “nasal planum”] that occurs seasonally)—Siberian huskies, Alaskan malamutes, yellow Labrador retrievers, and golden retrievers
  • Proliferative arteritis of the nasal philtrum (inflammation of the arteries of the nasal philtrum, the juncture between the sides of the upper lip extending to the nose)—Saint Bernards, giant schnauzers
  • Vitiligo in cats–Siamese
  • Periocular leukotrichia (whitening of the hair coat around the eyes) in cats–Siamese
  • Chediak-Higashi syndrome (an inherited disorder that affects many tissues in the body; causes lack of pigment in the skin and eyes)–Persian

Mean Age and Range

  • Vitiligo (condition characterized by symmetrical lack of pigment in the skin and white hair coat, especially involving the face and nose) in dogs—usually less than 3 years of age
  • Epitholiotropic lymphoma (a type of skin cancer; also known as “mycosis fungoides”)—typically dogs over 10 years of age

Predominant Sex

  • Discoid lupus erythematosus (auto-immune disease involving the skin only, usually the face)—may occur more often in females than in males
  • Vitiligo in Siamese cats—females

Signs/Observed Changes in the Pet

  • White hair (known as “leukotrichia”)
  • Partial or total lack of pigment in the skin (known as “leukoderma”)
  • Lightening of the pigment in the skin, often seen as a “graying” or “browning” of previously pigmented areas
  • Reddening of the skin (known as “erythema”)
  • Loss of the top surface of the skin (known as “erosion” or “ulceration,” based on depth of tissue loss)

Causes

  • Mucocutaneous pyoderma (bacterial skin infection involving areas of the lips, eyelids, nostrils)
  • Systemic lupus erythematosus (auto-immune disease in which the body attacks its own skin and other organs)
  • Discoid lupus erythematosus (auto-immune disease involving the skin only, usually the face)
  • Pemphigus foliaceous (auto-immune disease involving the skin, characterized by inflammation with crusting and lesions containing pus)
  • Pemphigus erythematosus (auto-immune disease involving the skin of the face and ears, characterized by reddening of the skin [erythema] and lesions containing pus)
  • Uveodermatologic syndrome (a rare syndrome in which the pet has inflammation in the front part of the eye, including the iris [anterior uveitis] and coexistent inflammation of the skin [dermatitis], characterized by loss of pigment in the skin of the nose and lips)
  • Contact hypersensitivity (increased sensitivity or reaction in the skin to the presence of a foreign agent that comes in contact with the skin)
  • Vitiligo (condition characterized by symmetrical lack of pigment in the skin and white hair coat, especially involving the face and nose)
  • Seasonal nasal depigmentation (loss of pigment in the tough, hairless skin of the nose [known as the “nasal planum”] that occurs seasonally)
  • Albinism (inherited disorders characterized by lack of pigment in the skin, hair, and/or eyes, due to abnormal production of melanin)
  • Schnauzer gliding syndrom (young, gray miniature schnauzers develop golden hair color, primarily in the body)
  • Hormonal disorders
  • Drug reaction
  • Erythema multiforme (skin disorder caused by reaction of medications, infections, or other diseases)
  • Proliferative arteritis of the nasal philtrum (inflammation of the arteries of the nasal philtrum, the juncture between the sides of the upper lip extending to the nose)
  • Loss of pigment in the skin and/or hair following skin inflammation
  • Dermatophytosis (fungal infection on the surface of the skin)

Risk Factors

  • Sun exposure—systemic lupus erythematosus (auto-immune disease in which the body attacks its own skin and other organs), discoid lupus erythematosus (auto-immune disease involving the skin only, usually the face), and pemphigus erythematosus (auto-immune disease involving the skin of the face and ears, characterized by reddening of the skin [erythema] and lesions containing pus)

Treatment

Health Care

  • Outpatient, except for systemic lupus erythematosus (auto-immune disease in which the body attacks its own skin and other organs), erythema multiforme (skin disorder caused by reaction to medications, infections, or other diseases), and lymphoma of the skin (a type of skin cancer), when severe multiple organ dysfunction is present
  • Reduce exposure to sunlight—systemic lupus erythematosus (auto-immune disease in which the body attacks its own skin and other organs), discoid lupus erythematosus (auto-immune disease involving the skin only, usually the face) and pemphigus erythematosus (auto-immune disease involving the skin of the face and ears, characterized by reddening of the skin [erythema] and lesions containing pus)
  • Replace plastic or rubber dishes—particularly if roughened edges cause abrasions
  • Application of water-resistant sun-block ointments or gels (with a SPF UVA and UVB greater than 30) to depigmented areas
  • Vitiligo and nasal depigmentation–no treatment

Activity

  • Restrict outdoor activity to minimize exposure to sunlight—systemic lupus erythematosus (auto-immune disease in which the body attacks its own skin and other organs), discoid lupus erythematosus (auto-immune disease involving the skin only, usually the face) and pemphigus erythematosus (auto-immune disease involving the skin of the face and ears, characterized by reddening of the skin [erythema] and lesions containing pus)

Surgery

  • Skin biopsy

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.

  • Vary based on underlying cause
  • Systemic lupus erythematosus (auto-immune disease in which the body attacks its own skin and other organs)—immunosuppressive therapy with steroids (such as prednisolone or dexamethasone) and chemotherapy drugs (such as azathioprine [dogs] or chlorambucil [cats])
  • Tetracycline and niacinamide—to treat pemphigus erythematosis (auto-immune disease involving the skin of the face and ears, characterized by reddening of the skin [erythema] and lesions containing pus) and discoid lupus erythematosus (auto-immune disease involving the skin only, usually the face) in dogs
  • Medications to decrease the immune response (known as “immunosuppressive therapy”)—to treat systemic lupus erythematosus (auto-immune disease in which the body attacks its own skin and other organs), pemphigus foliaceous (auto-immune disease involving the skin, characterized by inflammation with crusting and lesions containing pus), pemphigus erythematosus (auto-immune disease involving the skin of the face and ears, characterized by reddening of the skin [erythema] and lesions containing pus)
  • Cyclosporine to decrease the immune response in auto-immune disorders
  • Steroids applied to the skin directly (known as “topical steroids”)
  • Tacrolimus, 0.1% gel or pimecrolimus 1% cream applied daily to lesions in combination with or to replace steroids
  • Imiquimod 5% cream for actinic keratosis (a precancerous skin condition caused by sun exposure)
  • Antibiotics–trimethoprim-sulfadiazine, cephalexin, or amoxicillin-clavulanate; effective in some cats
  • Antibiotics for bacterial skin infection (known as “pyoderma”)
  • Chlorambucil, a chemoterapeutic drug
  • Medications to treat fungal infections (known as “antifungal drugs”) to treat dermatophytosis (fungal infection on the surface of the skin)

Follow-Up Care

Patient Monitoring

  • Varies with specific disease and treatment prescribed

Preventions and Avoidance

  • Restrict outdoor activity to minimize exposure to sunlight—systemic lupus erythematosus (auto-immune disease in which the body attacks its own skin and other organs), discoid lupus erythematosus (auto-immune disease involving the skin only, usually the face) and pemphigus erythematosus (auto-immune disease involving the skin of the face and ears, characterized by reddening of the skin [erythema] and lesions containing pus)

Possible Complications

  • Systemic lupus erythematosus (auto-immune disease in which the body attacks its own skin and other organs)—scarring
  • Squamous cell carcinoma ( a type of skin cancer) in cases of sun-damage to the skin, with resulting loss of skin pigment

Expected Course and Prognosis

  • Vary with specific disease

Mange (Demodectic)

Mange (Demodectic) – An Overview

  • An inflammatory parasitic skin disease of dogs and rarely cats, caused by a species of the mite genus, Demodex
  • Skin disease is characterized by an increased number of mites in the hair follicles and top layer of the skin (known as the “epidermis”), which often leads to secondary bacterial infections and infections deep in the hair follicles, often with resultant rupturing of the hair follicle (known as “furunculosis”)
  • May be localized (in which one or a few small patches of affected skin are present, frequently seen on the face or forelegs) or generalized (in which numerous skin lesions are present on the head, legs, and body)
  • “Demodectic mange,” “demodicosis,” and “red mange” (dogs) are all terms for the same skin disease
  • Three species of Demodex mites have been identified in dogs: Demodex canis, Demodex injai, and Demodex cornei; two species have been identified in cats:Demodex cati and Demodex gatoi

Genetics

  • The initial increase in number of demodectic mites in the hair follicles may be the result of a genetic disorder

Signalment/Description of Pet

Species

  • Dogs – common
  • Cats – rare

Breed Predilections

  • West Highland white terrier and wirehaired fox terrier—greasy inflammation of the skin with increased accumulations of surface skin cells, such as seen in dandruff (accumulations known as “scales”; condition known as “seborrheic dermatitis”) associated with Demodex injai
  • Potential of demodectic mange in cats is increased in Siamese and Burmese

Mean Age and Range

  • Localized demodectic mange (in which one or a few small patches of affected skin are present, frequently seen on the face or forelegs)—usually in young dogs; median age is 3–6 months
  • Generalized demodectic mange (in which numerous skin lesions are present on the head, legs, and body)—both young and old dogs
  • No age data collected for the cat

Signs/Observed Changes in the Pet

Dogs

Localized, Juvenile-Onset
  • One or a few small patches of affected skin are present, frequently seen on the face or forelegs
  • Lesions—usually mild; consist of reddened skin (known as “erythema”) and a light accumulations of surface skin cells, such as seen in dandruff (scales)
  • Patches—several may be noted; most common site is the face, especially around the mouth and eyes and on the front legs; also may be seen on the trunk and rear legs
Generalized, Juvenile-Onset or Adult-Onset
  • Numerous skin lesions are present on the head, legs, and body
  • Can be widespread from the onset, with multiple, poorly circumscribed patches of reddened skin (erythema), hair loss (known as “alopecia”), and accumulations of surface skin cells, such as seen in dandruff (scales)
  • As hair follicles become distended with large numbers of mites, secondary bacterial infections , often with resultant rupturing of the hair follicle (furunculosis) are common
  • With progression of disease, the skin can become severely inflamed, leading to the escape of fluid and inflammatory cells in or on the skin (known as “exudation”), and the development of nodular, inflammatory lesions (known as “granulomas”)
  • Demodex injai may be associated with a greasy inflammation of the skin with increased accumulations of surface skin cells, such as seen in dandruff (accumulations are “scales”; condition is “seborrheic dermatitis”) of the dorsal trunk, plugs of keratin and oil in the follicles of the skin (known as “comedones”), reddened skin (erythema), hair loss (alopecia), and darkening of the skin (known as “hyperpigmentation”)

Cats

  • Often characterized by multiple partial to complete areas of hair loss (alopecia) of the eyelids, as well as the skin around the eyes, head, neck, flank and the under surface of the body
  • Lesions—variable itchiness (known as “pruritus”) with reddened skin (erythema), accumulations of surface skin cells, such as seen in dandruff (scales), and dried discharge on the surface of the skin lesions (known as “crusts”); those caused by Demodex gatoi often are quite itchy (pruritic) and may be contagious
  • Inflammation of the outer ear, characterized by the presence of waxy material (known as “ceruminous otitis externa”) has been reported
  • Demodex cati often is associated with a disease that decreases the immune response (known as “immunosuppressive disease”)

Causes

  • Dog—Demodex canis, Demodex injai, and Demodex cornei
  • Cat—Demodex cati and Demodex gatoi

Risk Factors

Dogs

  • Exact mechanism related to the influence of the immune system on demodectic mange is unknown
  • Studies indicate that dogs with generalized demodectic mange (in which numerous skin lesions are present on the head, legs, and body) have a subnormal percentage of interleukin-2 (IL-2) receptors on their lymphocytes and subnormal IL-2 production; “lymphocytes” are a type of white-blood cell that are formed in lymphatic tissues throughout the body; lymphocytes are involved in the immune process
  • Genetic factors (especially for localized, juvenile-onset demodectic mange), decreased ability to produce a normal immune response (immunosuppression), and/or metabolic diseases may increase the likelihood that the dog will develop demodectic mange

Cats

  • Often associated with metabolic diseases (such as feline immunodeficiency virus [FIV], systemic lupus erythematosus [autoimmune disease in which body attacks its own skin and other organs], diabetes mellitus [sugar diabetes])
  • Demodex gatoi—may be transferable from cat to cat within the same household

Treatment

Health Care

  • Outpatient
  • Localized demodectic mange (in which one or a few small patches of affected skin are present, frequently seen on the face or forelegs)—conservative; most cases (90%) resolve spontaneously with no treatment
  • Generalized demodectic mange (in which numerous skin lesions are present on the head, legs, and body) in dogs—requires application of medication to kill the mites directly onto the skin (known as “topical treatment”) and/or medications administered by mouth (known as “systemic treatment”); antibiotics may be necessary to treat secondary bacterial skin infections
  • Evaluate the general health status of dogs with either localized or generalized demodectic mange

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

Amitraz (Mitaban; Taktic EC; ProMeris)

  • A treatment that is applied directly to the skin (topical treatment) to kill demodectic mange mites; agents that kill mites are known as “miticides”
  • Use weekly to every-other-week until resolution of clinical signs and no mites are found on skin scrapings; do not rinse off; let air-dry; use as directed by your pet’s veterinarian
  • ProMeris—apply to skin every 2–4 weeks
  • Treat for 1 month following negative skin scrape
  • Apply a benzoyl peroxide shampoo before application of the amitraz to kill bacteria (known as “bactericidal therapy”) and to increase exposure of the mites to the miticide through flushing activity of the hair follicles
  • Between 11% and 30% of cases will not be cured; may need to try an alternative therapy or control with maintenance treatment every 2–8 weeks
  • Rarely used in cats (do not use on diabetic cats)

Ivermectin

  • Dog—daily administration by mouth has been very effective, even when amitraz fails; use as directed by your pet’s veterinarian
  • Treat for 30–60 days beyond negative skin scrapings (average length of treatment is 3–8 months)
  • Reported as a treatment option in the cat; exact dose has not been established

Milbemycin (Interceptor)

  • Administered by mouth
  • Has been effective in 50–85% of cases
  • Treat for 30–60 days beyond multiple negative skin scrapings
  • Very expensive

Cats

  • Exact treatment protocols are not defined
  • Lime-sulfur dips applied to the skin (topical treatment) every 3–7 days for 4–8 treatments is the suggested treatment; often lead to good resolution of clinical signs
  • Studies of treatment with ivermectin and milbemycin are lacking, although numerous anecdotal reports suggest effectiveness
  • Doramectin also has been reported to be effective when given by injection under the skin (subcutaneous route) once weekly

Follow-Up Care

Patient Monitoring

  • Repeat skin scrapings and monitor for evidence of resolution of signs

Preventions and Avoidance

  • Do not breed pets with generalized form of demodectic mange (in which numerous skin lesions are present on the head, legs, and body)

Possible Complications

  • Secondary bacterial infections and infections deep in the hair follicles, often with resultant rupturing of the hair follicle (furunculosis)

Expected Course and Prognosis

  • Prognosis (dogs)—depends heavily on genetics, status of the immune system, and underlying diseases
  • Localized demodectic mange (in which one or a few small patches of affected skin are present, frequently seen on the face or forelegs)—most cases (90%) resolve spontaneously with no treatment; less than 10% of localized demodectic mange cases progress to generalized demodectic mange (in which numerous skin lesions are present on the head, legs, and body)
  • Adult-onset of demodectic mange in dogs—often severe disease and poorly responsive to non-responsive to treatment
  • Feline cases with Demodex cati may have a poor prognosis associated with underlying disease

Key Points

  • Localized demodectic mange (in which one or a few small patches of affected skin are present, frequently seen on the face or forelegs)—most cases resolve spontaneously
  • Generalized demodectic mange (in which numerous skin lesions are present on the head, legs, and body)—frequent management problem; expense and frustration with the long-term (chronic) nature of disease and treatment are issues; many cases are medically controlled, not cured; juvenile-onset is considered to have a genetic influence and affected animals should not be used for breeding

Itchiness in Dogs & Cats

Itchiness in Dogs & Cats – An Overview

  • “Pruritus” is the medical term for itching or itchiness; it is the itching sensation that provokes the desire to scratch, rub, chew or lick
  • Pruritus is an indicator of inflamed skin
  • The term is not a diagnosis but rather is a description of a clinical sign

Species

  • Dogs
  • Cats

Signs/Observed Changes in the Pet

  • Scratching
  • Licking
  • Biting
  • Rubbing
  • Chewing
  • Self-trauma
  • Inflammation of the skin (known as “dermatitis”)
  • Hair loss (known as “alopecia”); hair loss without inflammation may be the only sign in some cats
  • Other signs determined by underlying cause

Causes

  • Parasites—fleas; mites (canine scabies [Sarcoptes], Demodex, ear mites [Otodectes], feline scabies [Notoedres], “walking dandruff” [Cheyletiella], harvest mite or red bud [Trombicula]); lice; rhabditic dermatitis (Pelodera strongyloides); or migration of internal parasites
  • Allergies—parasite allergy; atopy (disease in which the pet is sensitized [or “allergic”] to substances found in the environment [such as pollen] that normally would not cause any health problems); food allergy; contact allergy; drug allergy; allergy to skin bacteria (known as “bacterial hypersensitivity”); allergy to Malassezia (a yeast found on the skin)
  • Bacterial or fungal infections—Staphylococcus (a bacteria) and Malassezia pachydermatis (a yeast or fungus); rarely a dermatophyte (fungus living on the skin, hair, or nails); however, Trichophyton is a dermatophyte that tends to cause more itchy skin disease than the other dermatophytes
  • Miscellaneous—excessive scaling of the skin (known as “seborrhea”); calcium deposits in the skin (known as “calcinosis cutis”); skin tumors or cancer
  • Immune-mediated skin diseases and hormonal skin diseases can be variably itchy
  • Psychological skin diseases may be associated with itchiness

Risk Factors

  • Exposure to other animals with parasites

Treatment

Health Care

  • More than one disease can contribute to itching
  • The use of mechanical restraint (such as an Elizabeth collar) can be a helpful option, but is seldom feasible in long-term treatment
  • Treat for secondary infections, which are common

Diet

  • Depends on underlying cause
  • Usually no change in diet needed, unless suspected food allergey

Medication

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

Medications Applied to the Skin Directly (Known as “Topical Therapy”)

  • Topical therapy is helpful in mildly itchy pets
  • For localized areas of itchiness or skin inflammation, sprays, lotions and creams are most appropriate
  • If the itching involves many areas or widespread areas, shampoos are the preferred means of application
  • Antibacterial shampoos help control bacterial infections that cause itching; however, some antibacterial shampoos (such as those containing benzoyl peroxide or iodine) can cause increased itching
  • Colloidal oatmeal is common in all forms of topical therapy; its duration of effect usually is less than two days
  • Topical antihistamines may be found alone or in combination with other ingredients; they may not have a beneficial effect
  • Topical anesthetics may offer only a very short duration of effect
  • Antimicrobial shampoos help control bacterial infections that cause itching; however, some contain ingredients (such as benzoyl peroxide or iodine) that can increase itchiness through excessive drying
  • Lime sulfur (which has a bad odor and can stain) can decrease itching, while also having anti-parasitic, antibacterial, and antifungal properties
  • Topical steroids probably are the most useful topical medications; hydrocortisone is the mildest and most common topical steroid; stronger steroids (such as betamethasone) may be more effective and are more expensive; a triamcinolone-containing prescription spray (Genesis® Topical Spray, Virbac) is effective in decreasing itchiness (pruritus)
  • Some topical steroid medications also contain ingredients (such as alcohol), which can aggravate already irritated skin
  • In some pets, the application of any substance, including water (especially warm water), can result in an increased level of itchiness; however, cool water often is soothing

Medications Administered by Mouth or by Injection (Systemic Therapy)

  • Steroids to decrease inflammation and itchiness of the skin
  • Cyclosporine to decrease the immune response
  • For pets affected with airborne allergies for more than a few months out of the year, “allergy shots” (known as “allergen specific immunotherapy”) are appropriate, frequently beneficial, and may lead to a cure (in some cases)
  • Antihistamines (such as hydroxyzine, diphenhydramine, and chlorpheniramine) to prevent inflammation and itching
  • Fatty acids are available in powders, liquids, and capsules; they help block pathways that lead to inflammation, but may require 6–8 weeks of use until maximum effect is observed; fatty acids work better as preventive medications, rather than stopping the inflammation once it has become a problem; they also help reduce dry or flaky skin, which can cause itching
  • Medications to relieve anxiety or depression (known as “psychogenic drugs”) can be helpful in controlling itchiness; include such drugs as amitriptyline, fluoxetine, and diazepam
  • In rare cases, alternative medications to decrease the immune response (known as “immunosuppressive drugs,” such as azathioprine) may be utilized; however, they should be reserved for instances when all other treatments have failed

Follow-Up Care

Patient Monitoring

  • Patient monitoring is imperative; pets should be examined periodically to evaluate response to treatment
  • Pets receiving long-term (chronic) medications should be evaluated every 3–12 months for potential side effects as well as occurrence of new contributing factors

Preventions and Avoidance

  • Prevent infestation with parasites (such as fleas and mites)
  • Avoid foods identified as causing food allergy for your pet

Possible Complications

  • Owner frustration is common
  • Complications (such as increased thirst [known as “polydipsia”] and increased urination [known as “polyuria”]) are common with long-term (chronic) steroid use

Expected Course and Prognosis

  • Depend on underlying cause
  • Many causes of itchiness in pets are extremely frustrating to control

Key Points

  • Many different unrelated diseases may contribute to itchiness (pruritus), and control of one disease does not mean that other causes cannot be contributing to itchiness or cannot occur later
  • Multiple causes (such as flea allergy, inhalant allergy, and bacterial skin infection [known as “pyoderma”]) commonly are present in a single patient
  • Elimination of bacterial skin infection (pyoderma) and flea-associated disease may not be enough to significantly reduce itchiness
  • Food-allergy and inhalant-allergic pets may do well during the winter season with a hypoallergenic diet, only to become itchy during the warmer months in association with inhalant allergies

Hair Loss with No Skin Inflammation

Hair Loss Without Inflammation of The Skin in Dogs — An Overview

  • “Alopecia” is the medical term for hair loss
  • Non-inflammatory alopecia is a group of uncommon skin disorders, characterized by hair loss that is associated with an abnormal hair growth/shed cycle
  • Hormonal and non-hormonal diseases can be associated with non-inflammatory hair loss (alopecia)
  • Alopecia X is a non-inflammatory alopecia related to an abnormal hair growth/shed cycle; it has been called by many names previously, including “growth hormone-responsive alopecia,” “castration-responsive alopecia,” and “adrenal hyperplasia-like syndrome”
  • “Estrogen,” “progesterone,” and “estradiol” are female hormones; “testosterone” and “androgen” are male hormones
  • An “intact” pet is one that has its reproductive organs; an “intact female” has her ovaries and uterus and an “intact male” has his testicles
  • A “neutered” pet has had its reproductive organs surgically removed; females commonly are identified as “spayed,” but may be identified as “neutered”; males may be identified as “castrated” or “neutered”

Genetics

  • Breed predilections exist for alopecia X; however, the mode of inheritance is unknown

Signalment/Description of Pet

Species

  • Dogs

Breed Predilections

  • Increased levels of estrogen (known as “hyperestrogenism”) in females and increased levels of androgen (known as “hyperandrogenism”) in males—none
  • Alopecia X—miniature poodle and plush-coated breeds, such as the Pomeranian, chow chow, Akita, Samoyed, Keeshonden, Alaskan malamute, and Siberian husky

Mean Age and Range

  • Increased levels of estrogen (hyperestrogenism) in females and increased levels of androgen (hyperandrogenism) in males—middle-aged to old, intact dogs
  • Alopecia X—range, 1–5 years of age; older dogs may develop alopecia X

Predominant Sex

  • Increased levels of estrogen (hyperestrogenism)—primarily intact female or male dogs; male dogs due to testicular cancer producing excessive levels of estrogen
  • Increased levels of androgen (hyperandrogenism)—primarily intact males
  • Alopecia X—neutered or intact dogs of either sex

Signs/Observed Changes in The Pet

  • Overall change in the hair coat—dry or bleached, because hairs are not being replaced; lack of normal shedding
  • Male dogs with increased levels of estrogen (hyperestrogenism) may attract other male dogs
  • Hair loss (alopecia)—usually generalized and bilaterally symmetrical; involves the trunk, along the sides of the body (known as “truncal alopecia”) and spares the head and lower legs; hair loss is uncommon in dogs with increased levels of androgens (hyperandrogenism)
  • Secondary excessively oily or dry scaling of the skin (known as “seborrhea”); itchiness (known as “pruritus”); skin infection characterized by the presence of pus (known as “pyoderma”); hair follicles filled with oil and skin cells (known as “comedones”); inflammation of the outer ear, characterized by an oily discharge (known as “ceruminous otitis externa”); and darkened skin (known as “hyperpigmentation”)—variable
  • Enlargement of nipples, mammary glands, vulva (external genitalia of the female), prepuce (fold of skin that covers the penis)—may be associated with increased levels of estrogen (hyperestrogenism)
  • Abnormal sized testicles—may be associated with increased levels of estrogen (hyperestrogenism) or increased levels of androgen (hyperadrogenism); however, testicles may be normal in size
  • Increase in the number of cells in the tail glands (known as “tail gland hyperplasia”) and increase in the number of cells in the perianal gland (known as “perianal gland hyperplasia”) with localized change in color of the skin due to deposits of melanin (known as “macular melanosis”)
  • Signs of generalized disease (known as “systemic signs”), such as increased thirst (known as “polydipsia”), increased urination (known as “polyuria”), or increased appetite (known as “polyphagia”) are NOT present

Causes

Skin Disorders due to Increased Levels of Estrogen (Hyperestrogenism)–Female

  • Estrogen excess or imbalance owing to a condition characterized by the presence of fluid-filled sacs or cysts in the ovaries (cystic ovaries), ovarian tumors (rare), or excess/overdose of estrogen-containing medications
  • Pets with normal serum estrogen concentrations may have a increased number of estrogen receptors in the skin

Skin Disorders due to Increased Levels of Estrogen (Hyperestrogenism)–Male Dogs with Testicular Tumors

  • Estrogen excess due to a tumor in the testicles, such as Sertoli cell tumor (most common), seminoma, or interstitial cell tumor (rarely)
  • Lack of normal descent of one or both testicles into the scrotum, resulting in the testicle(s) being located in the abdomen or inguinal canal (known as “cryptorchidism”) increases the likelihood that affected pets will develop testicular tumors
  • Associated with male pseudohermaphrodism in miniature schnauzers; “pseudohermaphrodism” is a condition where the pet has either ovaries or testicles, but has uncertain (ambiguous) external genitalia

Skin Disorder due to Increased Levels of Androgen (Known as “Hyperandrogenism”) Associated with Testicular Tumors

  • Androgen-producing testicular tumors (especially interstitial cell tumors) in intact male dogs

Alopecia X

  • Hairs fail to cycle normally; an underlying hormonal cause has not been identified

Risk Factors

  • Intact male and female dogs are at increased risk for developing testicular tumors and ovarian cysts/tumors, respectively
  • Lack of normal descent of one or both testicles into the scrotum, resulting in the testicle(s) being located in the abdomen or inguinal canal (known as “cryptorchidism”) increases the likelihood that affected pets will develop testicular tumors
  • Administration of medications containing estrogen
  • Alopecia X—breed (miniature poodle and plush-coated breeds, such as the Pomeranian, chow chow, Akita, Samoyed, Keeshonden, Alaskan malamute, and Siberian husky)

Treatment

Health Care

  • Depends on cause of skin disorder
  • Discontinue administration of estrogen-containing medications, as directed by your veterinarian, if excessive estrogen is the likely cause of the skin disorder

Surgery

  • Skin biopsy
  • Surgical removal of testicles (neuter or castration) of pets with lack of normal descent of one or both testicles into the scrotum, resulting in the testicle(s) being located in the abdomen or inguinal canal (cryptorchidism); neuter when young
  • Surgical removal of testicles (neuter or castration)— testicular tumors
  • Exploratory surgery (known as a “laparotomy”)—diagnosis and treatment (such as surgical removal of the ovaries and uterus [spay or ovariohysterectomy] and surgical removal of testicles located in the abdomen [castration]) for ovarian cysts and tumors and abdominal testicular tumors
  • Alopecia X—surgical removal of reproductive organs (ovariohysterectomy in females and neuter or castration in males) may lead to hair regrowth in some dogs; hair regrowth may take up to 3 months before becoming evident

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

General Treatment

  • Topical (applied to the skin directly) medication to treat seborrhea (known as “antiseborrheic therapy”)—conditions with associated keratinization defects and comedones (in which the hair follicles are filled with oils and skin cells)
  • Antibiotics—to treat associated skin infections, characterized by the presence of pus (pyodermas)

Alopecia X

  • Melatonin—hair regrowth can take up to 3 months to become evident; this treatment is effective in approximately 40% of affected dogs; should be tried following neutering; once hair growth has occurred, discontinue melatonin treatment
  • Other MedicationsConsider mitotane or o,p’-DDD (Lysodren) to stimulate hair regrowth in some dogs; can take up to 3 months for hair regrowth to become evident
  • Trilostane to stimulate hair regrowth in some dogs; can take up to 3 months for hair regrowth to become evident

Follow-Up Care

Patient Monitoring

  • Treatment with mitotane or o,p’-DDD (Lysodren)—bloodwork (electrolytes) and adrenocorticotropic hormone (ACTH)-stimulation testing regularly
  • Treatment with trilostane—bloodwork (electrolytes) and ACTH-stimulation testing regularly

Expected Coourse and Prognosis

  • Female increased levels of estrogen (hyperestrogenism)—improvement should occur within 3–6 months after surgical removal of the ovaries and uterus (spay or ovariohysterectomy)
  • Estrogen- and androgen-secreting tumors—resolution of signs noted within 3–6 months after surgical removal of the ovaries and uterus (spay or ovariohysterectomy) or the testicles (castration), respectively

Surgery

  • Biopsy of a tumor or the skin may be indicated in the diagnostic workup for some causes of hair loss (alopecia)
  • Hormonal disorders causing hair loss (treatment determined by specific hormonal disorder)—surgery may include removal of ovaries and uterus (known as “ovariohysterectomy” or “spay”), removal of testicles (known as “castration”), or removal of adrenal glands (known as “adrenalectomy”)
  • Surgical removal of skin cancer or tumors
  • Alopecia X–hair regrowth will occur only in some dogs, regardless of treatment; hair loss may recur in spite of continued treatment

Key Points

  • Alopecia X is a cosmetic condition, resulting in hair loss only; no cure has been determined to treat the hair loss; hair regrowth will occur only in some dogs regardless of treatment; hair loss may recur months to years later in spite of continued treatment

Hair Loss in Dogs (Canine Alopecia)

Hair Loss in Dogs (Canine Alopecia)–An Overview

  • “Alopecia” is the medical term for hair loss
  • Hair loss is a common disorder in dogs
  • Characterized by a complete or partial lack of hair in areas where it is present normally
  • Pattern of hair loss–varied or symmetrical
  • May be the primary problem or be secondary to an underlying cause
  • May be associated with a single cause or multiple causes

Signalment/Description of Pet

  • May be sudden (acute) in onset or slowly progressive
  • Multiple patches of circular hair loss (alopecia)—most frequently associated with inflammation of the hair follicles (known as “folliculitis”) from bacterial infection and/or demodectic mange (known as “demodicosis”)
  • Large, more widespread areas of hair loss (alopecia)—may indicate abnormal development of the hair follicles or hair (known as “follicular dysplasia”) or a more generalized disease
  • The pattern and degree of hair loss are important for establishing a diagnosis

Causes

Multiple Areas (Multifocal) of Hair Loss

  • Localized demodectic mange (demodicosis)—partial to complete hair loss (alopecia) with reddening of the skin (known as “erythema”) and mild scaling; lesions may become inflamed and may have dried discharge on the surface (dried discharge known as “crusts”)
  • Ringworm (known as “dermatophytosis”)—”ringworm” is a fungal infection on the surface of the skin characterized by partial to complete hair loss (alopecia) with scaling; with or without reddening of the skin (erythema); not always “ring-like” in appearance
  • Inflammation of the hair follicles due to Staphylococcus bacterial infection (known as “staphylococcal folliculitis”)—circular patterns of hair loss (alopecia) bordered by scales (accumulations of surface skin cells, such as seen in dandruff) or surface peeling of the skin (the pattern is known as an “epidermal collarette”), reddening of the skin (erythema), dried discharge on the surface of the skin lesion (crust), and darkened areas of skin (known as “hyperpigmented macules”)
  • Injection reactions—inflammation with hair loss (alopecia) and/or thinning of the skin (known as “cutaneous atrophy”) from scarring
  • Rabies-vaccine inflammation of the blood vessels (known as “vasculitis”)—well-demarcated patch of hair loss (alopecia) at the location where the rabies vaccine was administered is observed 2–3 months following vaccination
  • Localized scleroderma (condition in which normal skin is replaced by scar tissue for some unknown cause)—well-demarcated, shiny, smooth skin with hair loss (alopecia); lesion is a thickened, raised, flat-topped area that is slightly higher than the normal skin (known as a “plaque”)
  • Specific condition characterized by multiple patches of hair loss (known as “alopecia areata”)—non-inflammatory areas of complete hair loss (alopecia)
  • Condition characterized by multiple areas of hair loss with reddened skin, scales, and signs of itchiness (known as “pruritus”) with inflammation of the sebaceous glands, the glands that produce oils in the hair coat (condition known as “sebaceous adenitis”) seen in short-coated breeds—ring-like areas of hair loss (alopecia) and scaling

Symmetrical Hair Loss

  • Excessive levels of steroids produced by the adrenal glands (known as “hyperadrenocorticism” or “Cushing’s syndrome”)—hair loss along the sides of the body (known as “truncal alopecia”) associated with thin skin, plugs of keratin and oil in the follicles of the skin (known as “comedones”), and skin infection characterized by the presence of pus (known as “pyoderma”)
  • Inadequate levels of thyroid hormone (known as “hypothyroidism”)—hair loss (alopecia) is an uncommon presentation
  • Non-inflammatory hair loss (non-inflammatory alopecia, known as “alopecia X”)—symmetrical hair loss along the sides of the body (truncal alopecia) associated with darkened skin (known as “hyperpigmentation”); hair loss often starts along the collar area of the neck; seen in Pomeranians, chow chows, Akitas, Samoyeds, Keeshonden, Alaskan malamute, and Siberian husky
  • Excessive levels of estrogen (known as “hyperestrogenism”) in females—symmetrical hair loss (alopecia) of the flanks and skin between the external genitalia and the anus (perineal skin) and between the rear legs (inguinal skin) with enlarged external genitalia (vulva) and mammary glands
  • Inadequate secretion of female hormones (known as “hypogonadism”) in intact females—hair loss of the skin between the external genitalia and the anus (perineal skin), flank, and hair loss along the sides of the body (truncal alopecia)
  • Testosterone-responsive skin disorder (known as “testosterone-responsive dermatosis”) in castrated males—slowly progressive hair loss along the sides of the body (truncal alopecia)
  • Male feminization from Sertoli cell tumor (a type of tumor in the testicles)—hair loss (alopecia) of the skin between the external genitalia and the anus (perineal skin) and genital region with excessive development of the male mammary glands (known as “gynecomastia”)
  • Castration-responsive skin disorder (known as “castration-responsive dermatosis”)—hair loss (alopecia) in the collar area, rump, skin between the external genitalia and the anus (perineal skin), and flanks
  • Estrogen-responsive skin disorder (known as “estrogen-responsive dermatosis”) in spayed female dogs—hair loss (alopecia) of the skin between the external genitalia and the anus (perineal skin) and genital regions
  • Seasonal flank hair loss/cyclic flank hair loss (alopecia)—creeping hair loss involving the flanks with darkened skin (hyperpigmentation); seen in boxers, English bulldogs, and Airedale terriers

Patchy to Generalized (Diffuse) Hair Loss

  • Demodectic mange (demodicosis)—often associated with reddening of the skin (erythema), inflammation of the hair follicles (folliculitis), and darkened skin (hyperpigmentation)
  • Bacterial infection/inflammation of the hair follicles (folliculitis)—multiple areas of circular hair loss (alopecia) that may join to form large areas of hair loss; circular patterns of hair loss bordered by scales (accumulations of surface skin cells, such as seen in dandruff) or surface peeling of the skin (epidermal collarette)
  • Ringworm (dermatophytosis)—often accompanied by scales (accumulations of surface skin cells, such as seen in dandruff)
  • Sebaceous adenitis (condition characterized by multiple areas of hair loss with reddened skin, scales, and signs of itchiness [known as “pruritus”] with inflammation of the sebaceous glands, the glands that produce oils in the hair coat)—hair loss (alopecia) with thick, adherent scales; predominantly along the back line of the body, including the head
  • Color-mutant/dilution hair loss (alopecia)—thinning of the hair coat with secondary inflammation of the hair follicles (folliculitis) in some blue or fawn dogs
  • Abnormal development of the hair follicles or hair (known as “follicular dysplasia”)—slowly progressive hair loss (alopecia)
  • Hair loss during stages of the hair growth cycle—sudden (acute) onset of hair loss (alopecia)
  • Inadequate levels of thyroid hormone (hypothyroidism)—generalized (diffuse) thinning of the hair coat
  • Excessive levels of steroids produced by the adrenal glands (hyperadrenocorticism or Cushing’s disease)—hair loss along the sides of the body (truncal alopecia) with thin skin and formation of plugs of keratin and oil in the follicles of the skin (comedones)
  • Epitheliotropic lymphoma (type of cancer in the skin characterized by the presence of abnormal lymphocytes; a lymphocyte is a type of white-blood cell, formed in lymphatic tissue throughout the body)—widespread, generalized hair loss along the sides of the body (truncal alopecia) with scales (accumulations of surface skin cells, such as seen in dandruff) and reddening of the skin (erythema); later small, solid masses (known as “nodules”) and thickened, raised, flat-topped areas that are slightly higher than the normal skin (known as “plaques”) may form
  • Pemphigus foliaceus (a disease in which the body’s immune system attacks its own skin)—hair loss (alopecia) associated with the formation of scales (accumulations of surface skin cells, such as seen in dandruff) and dried discharge on the skin lesions (crusts)
  • Keratinization disorders (disorders in which the surface of the skin is abnormal)—hair loss (alopecia) associated with excessive scales (accumulations of surface skin cells, such as seen in dandruff) and greasy surface texture

Specific Locations of Hair Loss

  • Hair loss involving the ears (pinnal alopecia) or pattern baldness—miniaturization of hairs and progressive hair loss (alopecia); seen in dachshunds, greyhounds, American water spaniels, Portuguese water spaniels, Boston terriers, Manchester terriers, whippets, Italian greyhounds, Chihuahuas
  • Traction hair loss (alopecia)—hair loss on the top and sides of the head secondary to having barrettes or rubber bands applied to the hair
  • Post-clipping hair loss (alopecia)—failure to regrow hair after clipping; may be associated with disruption of the hair-growth cycle
  • Melanoderma (hair loss [alopecia] of Yorkshire terriers)—symmetrical hair loss with darkened skin of the ears, bridge of the nose, tail, and feet
  • Seasonal flank hair loss/cyclic flank hair loss (alopecia)—creeping hair loss of the flanks with darkened skin (hyperpigmentation); seen in boxers, English bulldogs, and Airedale terriers
  • Abnormal development of the hair follicles or hair involving black hairs only (known as “black hair follicular dysplasia”)—hair loss (alopecia) involving only the black-haired areas of the body
  • Inherited inflammatory disorder that affects the skin and muscles of unknown cause (condition known as “idiopathic familial canine dermatomyositis”) in collies and Shetland sheepdogs—hair loss (alopecia) of the face, tip of ears, tail, and digits; associated with scales (accumulations of surface skin cells, such as seen in dandruff) and dried discharge on the skin lesions (crusts), and scarring

Treatment

Health Care

  • Demodectic mange (demodicosis)—amitraz, ivermectin, milbemycin
  • Ringworm (dermatophytosis)—griseofulvin, ketoconazole, itraconazole, lime sulfur dips, terbinafine
  • Inflammation of hair follicles due to Staphylococcus bacterial infection (staphylococcal folliculitis)—shampoo and antibiotic therapy
  • Sebaceous adenitis (condition with hair loss, reddened skin, scales and inflammation of the oil-secreting sebaceous glands)—keratolytic shampoo, essential fatty acid supplementation, retinoids
  • Keratinization disorders (disorders in which the surface of the skin is abnormal)—shampoos, retinoids, vitamin D, cyclosporine

Surgery

  • Biopsy of a tumor or the skin may be indicated in the diagnostic workup for some causes of hair loss (alopecia)
  • Hormonal disorders causing hair loss (treatment determined by specific hormonal disorder)—surgery may include removal of ovaries and uterus (known as “ovariohysterectomy” or “spay”), removal of testicles (known as “castration”), or removal of adrenal glands (known as “adrenalectomy”)
  • Surgical removal of skin cancer or tumors

Medications

  • Vary with specific cause
  • Excessive levels of steroids produced by the adrenal glands (hyperadrenocorticism or Cushing’s syndrome)—mitotane (Lysodren), trilostane

Follow-Up Care

Patient Monitoring

  • Determined by specific cause

Preventions and Avoidance

  • Determined by specific cause

Possible Complications

  • Determined by specific cause

Expected Course and Prognosis

  • Determined by specific cause

Key Points

  • “Alopecia” is the medical term for hair loss
  • Hair loss is a common problem in dogs
  • Pattern of hair loss varies–may be localized or widespread
  • Skin itself may appear normal or may be abnormal

Risk Factors

  • Intact male
  • Co-existing behavioral problem, such as separation anxiety
  • Owners poorly informed or motivated to properly housetrain their dog

Flea Bite Hypersensitivity & Flea Control

Flea Bite Hypersensitivity & Flea Control – Overview

  • “Hypersensitivity” is an increased sensitivity or reaction in the skin due to the presence of a foreign substance; in flea-bite hypersensitivity, the foreign substance is found in flea saliva; the reaction is immune based and would be considered to be an “allergic” reaction
  • “Dermatitis” is the medical term for inflammation of the skin
  • “Antigens” are substances that induce sensitivity or immune response
  • “Flea-bite hypersensitivity”—hypersensitivity or allergic reaction to antigens in flea saliva, with or without evidence of fleas and flea dirt
  • “Flea-bite dermatitis”—inflammation of the skin due to the flea bite itself; it is not an allergic or hypersensitivity reaction, but rather an irritant response to flea bites

Genetics

  • Flea-bite hypersensitivity—unknown inheritance pattern; more common in breeds with atopy (disease in which the pet is sensitized [or “allergic”] to substances found in the environment [such as pollen] that normally would not cause any health problems)

Signalment/Description of Pet

Species

  • Dogs
  • Cats

Mean Age and Range

  • Flea-bite hypersensitivity—rare in pets less than 6 months of age; average age range, 3–6 years, but may be seen at any age

Signs/Observed Changes in the Pet

  • Determined by the severity of the reaction and the degree of exposure to fleas (that is, seasonal or year-round)
  • Itchiness (known as “pruritus”)
  • Compulsive biting
  • Chewing (“corncob nibbling”)
  • Licking, primarily in the back half of the body, but may include the areas
  • Signs of fleas and flea dirt; finding fleas and flea dirt is beneficial, although not essential, for the diagnosis of flea-bite hypersinsitivity
  • Sensitive pets require a low exposure to fleas to have an immune response and they tend to over groom, removingt evidence of flea infestation, and making identification of parasites difficult
  • Hair loss (known as “alopecia”)
  • Small, raised skin lesions (known as “papules”)
  • Darkened skin (known as “hyperpigmentation”) in dogs
  • Thickening and hardening of the skin, usually associated with hyperpigmentation (known as “lichenification”) in dogs
  • “Hot spots” in dogs
  • Miliary dermatitis (skin inflammation characterized by numerous, small, crusty bumps) in cats)

Causes

  • Fleas
  • Immune response to flea saliva (flea-bite hypersensitivity or flea-allergy dermatitis)

Risk Factors

  • Flea-bite hypersensitivity—intermittent exposure to fleas increases likelihood of development; commonly seen in conjunction with atopy (disease in which the pet is sensitized [or “allergic”] to substances found in the environment [such as pollen] that normally would not cause any health problems)

Treatment

Health Care

  • Outpatient treatment

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.

  • Steroids—to decrease inflammation in the skin for symptomatic relief, while instituting flea control
  • Antihistamines–symptomatic relief
  • Flea control on the pet; examples include dinotefuran/pyriproxyfen (monthly spot treatment; rapid acting; two products—one for cats and one for dogs; dog product contains high dose of the insecticide, permethrin, and should NOT be used on cats); fipronil (monthly spot treatment for dogs and cats and spray treatment for dogs); imidacloprid (monthly spot treatment for cats and dogs); metaflumizone (monthly spot treatment for dogs or cats; product for dogs contains another active ingredient [amitraz] and should not be used on cats)
  • Flea control using medications given by mouth (known as “oral medications”)—nitenpyram (rapid action, but short-acting; kills over 95% of adult fleas on dogs and cats within 4–6 hours of administration, lasts for 48–72 hours); spinosad (monthly oral treatment for dogs only)
  • Other flea control for pets (such as flea sprays and other topical treatments)—usually contain pyrethrins and pyrethroids (synthetic pyrethrins) with an insect-growth regulator or synergist; generally effective for less than 48–72 hours
  • Environmental/indoor treatment—professional exterminator or home-use fogs and premises sprays; products usually contain organophosphates, pyrethrins, and/or insect-growth regulators; apply according to manufacturer’s directions; treat all areas of the house
  • Environmental/indoor treatment using inert substances—boric acid, diatomaceous earth, and silica aerogel; treat every 6–12 months; follow manufacturer’s recommendations
  • Environmental/outdoor treatment—concentrate outdoor treatment in shaded areas; sprays usually contain pyrethroids or organophosphates and an insect-growth regulator; a product containing nematodes (Steinerma carpocapsae) is chemical-free
  • Other products for use include flea powders, dips, sprays, and foams
  • NOTE: Always read all label instructions and follow the manufacturer’s directions when using any flea-control product; ensure that the product is labeled for use on the species (dog or cat) or location (indoors or outdoors) for which you intend to apply it—for example, some products that are safe for dogs are very toxic to cats and should not be used on cats

Follow-Up Care

Patient Monitoring

  • Itchiness (pruritus)—a decrease in itchiness indicates the flea infestation and/or flea-bite hypersensitivity is being controlled
  • Fleas and flea dirt—absence is not always a reliable indicator of successful treatment in very sensitive pets

Preventions and Avoidance

  • Year-round warm climates—year-round flea control is required
  • Seasonally warm climates–begin flea control in May or June, as directed by your pet’s veterinarian

Possible Complications

  • Secondary bacterial infections
  • Sudden (acute) moist dermatitis, also known as “hot spots”
  • Acral lick dermatitis (inflammation of the skin characterized by a firm, ulcerated lesion on a leg, caused by consistant licking)

Expected Course and Prognosis

  • Prognosis is good, if strict flea control is instituted

Key Points

  • Flea control is important for dogs and cats
  • No cure exists for flea-bite hypersensitivity
  • Flea-allergic pets often become more sensitive to flea bites as they age
  • Controlling exposure to fleas is currently the only means of controlling signs; “allergy shots” (known as “hyposensitization”) for flea-bite hypersensitivity are not effective