Feline Asthma: Bronchitis Syndrome in Cats
Asthma is a condition caused by constriction of the air passages in the lungs. (Bronchial Constriction or Irritation) The exact cause is not known, but asthma is a result of allergies and perhaps some other factors. Some cats get asthma from inhaling dust from their litter box, for example.
Affected cats suffer episodes of difficult breathing, and many have periods of severe coughing. Asthma attacks usually recur and are difficult to predict. Many months may pass between attacks or they may occur several times per day.
When you bring your cat to a vet for wheezing, coughing, or difficult breathing, the first thing we're likely to do is try to rule out other causes of respiratory disease. Other causes of mid and upper airway disease include:
Heartworms
(yes, cats get heartworms; go to heart page for info)
Heart Disease, especially cardiomyopathy
Lymphoma and other lung cancers
Cold Complex/kennel cough and other viral resp diseases
Bacterial or Fungal Respiratory Infections
Food Allergies (Maybe)
FIP, Aids, and Leukemia
Draining gum abscesses, oral herpes ulcers, and other oral ulcers
Second Hand Smoke (Maybe)
Parasites (many intestinal parasites spend part of their life cycle in the lungs)
Stress (Maybe)
Diaphramatic Hernia (Not likely but possible)
Hairballs etc ( the gassy bowel compresses the diaphram into the lungs)
Your experienced vet will be able to narrow the possiblities down with a good history and exam. We have blood tests that are able to quickly rule out heartworms, Aids, and Leukemia. Your vet may want to culture your cat's airways.
One of the most helpful diagnoistic tools, though, is a set of chest x-rays. X-rays help us rule out heart disease, lung masses, hernias, foreign bodies, and collasped lungs.
The above 2 x-rays are of a normal cat on the left and a cat with bronchial disease on the right. Your vet is trained to see the thickening of the bronchi and airways. Pretty cool, ey?
Treatment
In cats with very mild asthma or bronchitis and infrequent attacks of coughing, treatment may not be necessary at all. Mild to moderate conditions are treated medically at home by administration of medications designed to open up the bronchial tubes, and might include antibiotics, anti-oxidants, omega 3 fatty acids, bronchodilators, diet changes, or steroids. Steroids tend to be the most effective treatment, but are also the most likely to cause potentially serious side effects.
This is definitely the type of disease that will require a few rechecks and some trial and error adjustments of the treatment in hopes of making your cat comfortable and long lived.
Feline Bronchitis or Asthma
From The
TEXTBOOK OF VETERINARY INTERNAL MEDICINE
Client Information Series Dr. Carol Norris
Feline bronchitis, commonly called feline asthma, is a disease in cats affecting the smaller airways that branch off the windpipe (trachea). These branches, called bronchi, allow the transport of air into and out of the lungs. When the bronchi become obstructed because of constriction or con-traction of the muscles in the walls of these airways, the inflammation or irritation of the airways, or excessive secretions that plug the insides of the airways, the end result is an impaired ability to bring oxygen into the lungs for delivery to the rest of the body. Although the term "asthma" is commonly used to describe this syndrome in cats, this term is somewhat misleading.
Asthma, in people, specifically refers to the reversible constriction of muscles in the walls of the bronchi. Some cats have true asthma, whereas others have bronchitis. Bronchitis is associated with inflammation and swelling of the walls of the bronchi that cause a narrowed passageway and airway obstruction by plugs of mucus or other secretions, which also narrows these tubes. Bronchitis can be acute (short duration) and associated with reversible changes in the structure of the airways or chronic (long duration, usually more than 2 to 3 months) and associated with permanent, irreversible changes in the airways.
Bronchitis and asthma can occur at the same time and can be caused by bacterial infections, parasites, allergies, or inhaled irritants; in many cases, the underlying cause cannot be found.
The most common signs of bronchitis in cats include constant, cyclic, or seasonal coughing; difficulty breathing; and/or wheezing. Episodes of coughing can mimic vomiting; some owners think their cats are vomiting up hairballs when they are truly having a coughing fit followed by retching.
Breathing may be rapid or require excessive effort; some severely affected cats may breathe with their mouths open. If your cat ever displays any of these symptoms, it should be promptly taken to your veterinarian for further evaluation, as these signs are a warning of potentially serious disease. These signs are not specific for bronchitis and can also be seen with many other diseases including heart failure, pneumonia, and lung cancer.
In the diagnosis of feline bronchitis by your veterinarian, the first test is usually to take a radiograph (x-ray) of the chest.
Second, your veterinarian may recommend obtaining a sample of cells from the trachea and bronchi to examine under a microscope and to culture for any infectious organisms.
It is also common to check the blood and feces for parasites (heartworm and lung worm, respectively).
There are several principles to follow in the treatment of feline bronchitis.
First, any underlying disease (for example, bacterial or parasitic infection) must be appropriately diagnosed and treated.
Second, changes must be made in the cat's environment, since cats with bronchitis often have sensitive, hyperactive airways, and inhalation of irritating particles from the environment can cause worsening of their disease. Consequently, it is strongly recommended that their exposure to smoke (cigarette or fireplace), dusts (cat litter, carpet fresheners, flea powder), and sprays (insecticides, hair spray, perfumes, and cleaning products) be eliminated or minimized.
Third, weight reduction in obese cats should be attempted under the supervision of a veterinarian. Finally, medication should be given to treat the airway obstruction directly.
Two classes of drugs are commonly prescribed:
bronchodilators (examples include theophylline, aminophylline, and terbutaline) and steroids (examples include prednisone, dexamethasone, and methlyprednisone).
Bronchodilators help to dilate or open the airways by relaxing the muscular walls. Common side effects of bronchodilators in cats can include gastrointestinal upset, restlessness, and lethargy.
Steroids decreases the inflammation and swelling of the airway walls. Side effects in cats are uncommon but may include behavioral changes.
It is important that your cat have regular rechecks with your veterinarian, as the doses of the medications commonly need to be adjusted. Prognosis is variable for this disease. If the underlying cause can be identified and successfully treated or eliminated, the prognosis is excellent. If permanent damage to the airways has occurred, the disease cannot be cured. With proper medical management, clinical signs can be controlled and the damage to the bronchi can be stopped or slowed.
Some cats suffering severe asthma attacks can die despite intensive medical efforts.
