Asthma and Bronchitis in Cats

Asthma and Bronchitis in Cats – Overview

  • “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)
  • Asthma—sudden (acute) or long-term (chronic) inflammation of the lower airways, associated with increased responsiveness of the airways to various stimuli, airway narrowing, and presence of eosinophils, lymphocytes, and mast cells within the airways; “eosinophils” are a type of white blood cell—they are involved in allergic responses by the body and are active in fighting larvae of parasites; “lymphocytes” are a type of white blood cell that are formed in lymphatic tissues throughout the body—they are involved in the immune process; “mast cells” are immune-system cells that frequently are located near blood vessels—they contain histamine and are involved in allergy and inflammation
  • Long-term (chronic) bronchitis—inflammation in the lower airways (bronchi and bronchioles); chronic daily cough of greater than 2 months’ duration
  • The terms “feline bronchitis” and “feline bronchopulmonary disease” are used to describe the clinical syndrome in cats of sudden (acute) or long-term (chronic) coughing and/or wheezing (squeaking or whistling sounds) due to lower airway inflammation

Genetics

Species

      • Cats

Breed Predilections

      • Siamese appear to be more likely to develop asthma or bronchitis than other breeds

Mean Age and Range

      • Any age; more common between 2 and 8 years of age

Predominant Sex

    • One study indicated that females are more likely to develop asthma or bronchitis than males

Signs/Observed Changes in the Pet

  • Coughing (80%), sneezing (60%), labored breathing or wheezing (40%)
  • Signs typically are episodic and can be sudden (acute) or long-term (chronic)
  • Severely affected cats have open-mouth breathing, rapid breathing (known as “tachypnea”), and bluish discoloration of the skin and moist tissues (known as “mucous membranes”) of the body, caused by inadequate oxygen levels in the red blood cells (known as “cyanosis”)
  • Increased sensitivity to feeling the windpipe (trachea) is common
  • Listening to the chest with a stethoscope (known as “chest auscultation”) may reveal short, rough snapping sounds (known as “crackles”) and/or squeaking or whistling sounds (wheezes), or may be normal
  • Labored breathing, with an increase in expiratory effort; “expiratory effort” refers to the act of expiration or exhalation (breathing out)

Causes

  • Triggers or causes of airway inflammation are unknown

Risk Factors

  • Cigarette smoke, dusty cat litter, hair sprays, and air fresheners may make the disease worse
  • Parasitic lung infections are more common in outdoor cats in certain geographic locations
  • Use of potassium bromide (treatment for seizures) has been implicated causing signs of asthma or bronchitis in some cats

Treatment
Health Care

  • Remove cat from the inciting environment
  • Pet should be hospitalized for a sudden (acute) respiratory distress
  • Oxygen therapy and sedatives in a sudden (acute) crisis, characterized by breathing distress
  • Minimize handling during a crisis, in order to lessen stress and oxygen needs of the cat

Activity

  • Usually self-limited by the cat

Diet

  • Calorie restriction for obese cats

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

Emergency Treatment

      • Combine the use of oxygen and a medication that enlarges the bronchi and bronchioles in the lungs, administered by injection (medication known as a “parenteral bronchodilator”)
      • Terbutaline is a β-2 agonist that is used as a bronchodilator; administered by injection
      • A sedative (such as butorphanol, buprenorphine, or acepromazine) can aid in decreasing anxiety
      • A short-acting steroid, administered by injection, also may be required, such as dexamethasone sodium phosphate or prednisolone sodium succinate (Solu-Delta-Cortef), administered by injection, also can be used

Long Term Management

Steriods

      • Decrease inflammation
      • Steroid administered by mouth (oral treatment) is preferred over administration by injection, because doses and duration can be monitored more closely; steroids such as prednisolone; administer steroids as directed by your pet’s veterinarian
      • Some cats only need steroids on a seasonal basis
      • Longer-acting injectable steroids (such as Vetalog or Depomedrol) should be reserved only for situations in which owners are unable to administer medication by mouth on a routine basis
      • Inhaled steroids—require a form-fitting face mask, spacer, and metered-dose inhaler; veterinary brands include AeroKat (Trudell Medical International) or NebulAir (DVM Pharmaceuticals); the most commonly used inhaled steroid in cats is fluticasone propionate (Flovent); Flovent is used for long-term control of airway inflammation (takes 10–14 days to reach peak effect; during this time steroids administered by mouth should be used as well)

Other Drugs

    • Medications to enlarge or dilate the bronchi and bronchioles (bronchodilators), such as theophylline
    • β-2 agonists (terbutaline, albuterol)—inhibit smooth muscle constriction to dilate the bronchi and bronchiolesInhaled medications to enlarge or dilate the bronchi and bronchioles (bronchodilators)—albuterol is the preferred inhalant therapy in cats, providing immediate relief of spasm and constriction of the bronchi—its effect lasts less than 4 hours; ipratropium bromide can dilate the bronchi, and can be combined with albuterol to provide maximal dilation of bronchi
    • Medications to kill intestinal parasites (known as “anthelminthics”)—routinely recommended for cats with clinical signs of feline bronchopulmonary disease, with predominantly eosinophils found on microscopic examination of material obtained from the lower airways; parasitic inflammation of the bronchi and bronchioles (bronchitis) can be difficult to diagnose—treatment is indicated with appropriate clinical signs and geographic location; appropriate medication will depend on specific parasite suspected in the geographic region; examples include fenbendazole, ivermectin, or praziquantel
    • Antibiotics—choice of antibiotic based on bacterial culture and sensitivity testing
    • Cyproheptadine—inhibits airway smooth muscle constriction in experimental studies; unknown effects in cats with asthma/bronchitis
    • Cyclosporine (Neoral or Gengraf)—decreases the immune response; may be helpful in cats that do not respond to medications to enlarge or dilate the bronchi and bronchioles (bronchodilators) and steroid treatment

Follow-Up Care
Patient Monitoring

  • Report any increase in coughing, sneezing, wheezing, or breathing distress; medications should be increased appropriately if clinical signs worsen, as directed by your pet’s veterinarian
  • Follow-up x-rays (radiographs) may be helpful to evaluate response to medical treatment
  • Watch for signs of increased urination (known as “polyuria”) and increased thirst (known as “polydipsia”) that may indicate diabetes mellitus or kidney disease
  • Monitor blood glucose levels
  • Monitor urine (urinalysis, bacterial culture and sensitivity) as urinary tract infections can occur as a complication of treatment

Preventions and Avoidance

  • Eliminate any environmental factors (such as cigarette smoke, dusty cat litter, hair sprays, and air fresheners) that may trigger a crisis situation
  • Consider dust-free cat litter
  • Change furnace and air-conditioner filters on a regular basis

Possible Complications

  • Sudden (acute) episodes can be life-threateningUntreated sudden (acute) episodes can be life threatening
  • Right-sided heart disease may develop as a result of long-term inflammation of the bronchi and bronchioles (bronchitis)

Expected Course and Prognosis

  • Long-term therapy should be expected
  • Most cats do well, if recurrence of clinical signs is monitored carefully and medical therapy is adjusted appropriately
  • A few cats will not respond to medical treatment; these cats carry a much worse prognosis

Key Points

  • Most affected cats have long-term (chronic) and progressive disease
  • Sudden (acute) episodes can be life-threatening
  • Do not discontinue medical treatment when clinical signs have resolved—subclinical inflammation is common and can lead to progression of disease
  • Lifelong medication and environmental changes usually are necessary

Arthritis in Cats

Arthritis in Cats – Overview

  • “Arthritis” is the medical term for inflammation of the joints; “osteoarthritis” is a form of joint inflammation (arthritis) characterized by long-term (chronic) deterioration or degeneration of the joint cartilage
  • Progressive and permanent deterioration of joint cartilage
  • Also known as “degenerative joint disease” or DJD

Genetics

  • Cats—causes of secondary degenerative joint disease (progressive and permanent deterioration of joint cartilage) are dislocation of the kneecap (patellar luxation), abnormal development of the hip (hip dysplasia), and any joint disease (known as an “arthropathy”)

Affects

  • Cats
  • Dogs

Signs/Observed Changes in the Pet

  • Secondary degenerative joint disease (progressive and permanent deterioration of joint cartilage) due to congenital (present at birth) disorders (such as hip dysplasia) seen in immature pets; some present with DJD signs when older (such as cases of hip or elbow dysplasia)
  • Secondary to trauma—any age
  • Cats—obvious lameness may not be seen; instead, may have difficulty grooming, jumping onto furniture, or accessing the litter box; may have increased irritability
  • Stiff-legged or altered gait (such as “bunny hopping” in hip dysplasia)
  • Not using the affected leg(s)
  • Decreased range of motion
  • Grating detected with joint movement (known as “crepitus”)
  • Joint swelling (fluid buildup in the joint [known as “joint effusion”] and/or thickening of the joint capsule)
  • Joint pain
  • Joint instability
  • Obvious joint deformity

Causes

  • Primary—no known cause (so-called “idiopathic osteoarthritis”)
  • Secondary—results from an initiating cause, such as abnormal wear on normal cartilage (examples, secondary to joint instability, abnormal joints, trauma to cartilage or supporting soft tissues) or normal wear on abnormal cartilage (example, secondary to defects in the bone and cartilage [known as “osteochondral defects”])

Treatment
Health Care

  • Medical treatment—usually tried initially
  • Physical therapy—very beneficial
  • Maintaining or increasing joint motion—passive range of motion exercises
  • Pain management—cold and heat therapy
  • Muscle tone/strengthening exercise

Activity

  • Limited to a level that minimizes aggravation of clinical signs

Diet

  • Weight reduction for overweight pets—decreases stress placed on arthritic joints
  • Omega fatty acids may decrease inflammation

Surgery

  • Surgical options—improve joint geometry or remove bone-on-bone contact areas
  • Surgical procedure cutting into or entering a joint (known as an “arthrotomy”)—used to remove aggravating causes (such as bone and/or cartilage fragments or flaps)
  • Using a special lighted instrument called an “arthroscope” (general term for procedure is “arthroscopy”) to allow the surgeon to see inside the joint—used to diagnose and remove aggravating causes; flushing the joint may be beneficial
  • Reconstructive procedures—used to eliminate joint instability and correct structural or anatomic problems (such as in pets with dislocation of the kneecap [patellar luxation])
  • Joint removal—such as removal of the femoral head (the “ball”) of the hip joint for cases of abnormal development of the hip (hip dysplasia; procedure known as “femoral head and neck ostectomy” or FHO)
  • Joint replacement—total hip replacement is common; total elbow replacement still is experimental
  • Joint fusion (known as “arthrodesis”)—in selected long-term (chronic) cases and for joint instability

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
  • Nonsteroidal anti-inflammatory drugs (NSAIDs) to decrease pain and inflammation—examples are carprofen, deracoxib, etodolac, meloxicam, and tepoxalin for dogs; meloxicam for cats
  • Medications intended to slow the progression of arthritic changes and protect joint cartilage (known as “chondroprotective drugs”), such as polysulfated glycosaminoglycans, glucosamine, and chondroitin sulfate; examples include Adequan, Cosequin, Glyco-Flex, and Syn-flex—may help limit cartilage damage and degeneration; may help alleviate pain and inflammation
  • Steroids—decrease inflammation; however, long-term (chronic) use may delay healing and may initiate damage to joint cartilage; examples of steroids are prednisone administered by mouth or triamcinolone administered by injection into the joint (known as an “intra-articular injection”)

Follow-Up Care
Patient Monitoring

  • Clinical deterioration—indicates need to change drug selection or dosage; may indicate need for surgical intervention

Preventions and Avoidance

  • Early identification of conditions that may lead to osteoarthritis and prompt treatment to help reduce progression of secondary conditions

Expected Course and Prognosis

  • Slow progression of disease likely
  • Medical or surgical treatment usually allows a good quality of life

Key Points

  • Medical therapy is designed to control signs of osteoarthritis (known as “palliative treatment”) and not to cure the condition
  • Slow progression of disease likely
  • Medical or surgical treatment usually allows a good quality of life
  • Discuss treatment options, activity level, and diet with us

Acetaminophen Toxicity in Cats

Acetaminophen Toxicity in Cats – Overview

  • Results from owners overdosing the cat with over-the-counter medications containing acetaminophen, a medication intended to control pain or fever in humans

Genetics

  • Cats—genetic deficiency in a pathway that breaks down or changes (metabolizes) drugs in the liver (known as the “glucuronide conjugation pathway”); makes cats vulnerable to acetaminophen toxicity

Affects

  • Cats
  • Dogs
  • Most common drug toxicity in cats; considerably less frequent in dogs
  • Young and small dogs and cats—greater risk from owner-given single-dose acetaminophen medications

Signs/Observed Changes in the Pet

  • May develop 1–4 hours after dosing
  • Progressive depression
  • Rapid breathing
  • Darkened mucous membranes (moist tissues of body, such as gums)
  • Drooling (salivation)
  • Vomiting
  • Abdominal pain
  • Rapid breathing (known as “tachypnea”) and bluish discoloration of skin and moist tissues of body (known as “cyanosis”) due to a abnormal compound (methemoglobin) in the blood (condition known as “methemoglobinemia”) that disrupts the ability of the red blood cells to carry oxygen to the body
  • Fluid buildup (edema)—face, paws, and possibly forelimbs; after several hours
  • Chocolate-colored urine due to the presence of blood in the urine (known as “hematuria”) and the presence of methemoglobin in the urine (known as “methemoglobinuria”); especially in cats
  • Death

Causes

  • Acetaminophen overdosing

Treatment
Health Care

  • With methemoglobinemia (abnormal compound [methemoglobin] in the blood that disrupts the ability of the red blood cells to carry oxygen to the body)—must evaluate promptly; inpatient care
  • With dark or bloody urine or yellowish discoloration of skin and moist tissues of the body (known as “jaundice” or “icterus”)—inpatient care
  • Gentle handling—imperative for clinically affected pets
  • The veterinarian will induce vomiting (known as “emesis”) and may perform flushing of the stomach (known as “gastric lavage”)—useful within 4–6 hours of ingestion of acetaminophen
  • Low red blood cell count (known as “anemia”), blood in the urine (hematuria), or presence of hemoglobin in the urine (known as “hemoglobinuria”)—may require whole blood transfusion
  • Fluid therapy to maintain hydration and electrolyte balance
  • Drinking water should be available at all times

Activity

  • Restricted

Diet

  • Food—offered 24 hours after initiation of 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
  • Activated charcoal—administered immediately after the veterinarian has induced vomiting or flushed the stomach (gastric lavage) and after vomiting is controlled; activated charcoal is used to attract and keep the remaining acetaminophen in the gastrointestinal tract
  • N-acetylcysteine (Mucomyst®) is administered; considered to be an antidote for acetaminophen toxicity
  • Other sulfur donor drugs—if N-acetylcysteine not available; sodium sulfate
  • 1% methylene blue solution—combats methemoglobinemia without inducing red blood cell destruction (known as a “hemolytic crisis”)
  • Ascorbic acid—slowly reduces methemoglobinemia

Follow-Up Care
Patient Monitoring

  • Continual clinical monitoring of methemoglobinemia (abnormal compound [methemoglobin] in the blood that disrupts the ability of the red blood cells to carry oxygen to the body)
  • Serum liver enzyme activities to monitor liver damage
  • Blood glutathione level—provide evidence of the effectiveness of therapy

Preventions and Avoidance

  • Never give acetaminophen to cats
  • Give careful attention to acetaminophen dose in dogs; acetaminophen should only be given to dogs under a veterinarian’s supervision

Possible Complications

  • Liver damage and resulting scarring (fibrosis)—may compromise long-term liver function in recovered pets

Expected Course and Prognosis

  • Rapidly progressive methemoglobinemia (abnormal compound [methemoglobin] in the blood that disrupts the ability of the red blood cells to carry oxygen to the body)—serious sign
  • Methemoglobin concentrations greater than 50%—grave prognosis
  • Progressively rising serum liver enzymes 12–24 hours after ingestion—serious concern
  • Expect clinical signs to persist 12–48 hours; death owing to methemoglobinemia possible at any time
  • Dogs and cats receiving prompt treatment that reverses methemoglobinemia and prevents excessive liver damage may recover fully
  • Dogs—death as a result of liver damage may occur in a few days
  • Cats—death as a result of methemoglobinemia occurs 18–36 hours after ingestion

Key Points

  • Never give acetaminophen to cats
  • Acetaminophen should only be given to dogs under a veterinarian’s supervision
  • Most common drug toxicity in cats; considerably less frequent in dogs
  • Treatment in clinically affected pets may be prolonged and expensive
  • Pets with liver injury may require prolonged and costly management