Feline asthma
General information
Other common/scientific names: Feline allergic asthma, feline allergic bronchitis, feline eosinophilic bronchitis, feline lower airway disease, chronic allergic bronchitis
Feline asthma causes constriction of the airways which leads to difficulty breathing. The breathing problems caused by feline asthma can range from mild to life-threatening. Cats usually first show signs of the disease when they are young to middle-aged.
Causes
Feline asthma is believed to be primarily allergic in origin. When an allergen triggers certain immune cells in the cat’s body, the body responds by constricting the bronchi. Inflammation of the airways also occurs, and excessive mucus is produced in the airways. When these things occur, normal gas exchange cannot take place in the lungs, and the body will not be able to easily receive enough oxygen.
In general, the body’s reaction to an allergen increases with repeated exposure to the allergen. Thus, a cat’s asthma may become more and more severe each time the cat has an asthma attack. With repeated attacks, more and more structural changes can take place in the cat’s lungs, further reducing the diameter of the airways and further increasing respiratory difficulty with each asthma attack. Note, however, that even a cat’s first asthma attack may be life-threatening.
Although any breed of cat can be affected, Siamese cats appear to have a genetic predisposition to developing feline asthma. In addition to allergens, stress may also be a factor in triggering feline asthma.
Cardinal symptom
Difficulty breathing
Symptoms
Feline asthma causes a lack of oxygen which leads to shortness of breath and difficulty breathing. A cat with feline asthma might first be noticed taking rapid, shallow breaths, often with labored chest movements. Coughing and wheezing are also common, and the cat may be seen sitting slightly hunched over, with its elbows extended out to its sides. Open-mouth breathing, gasping for air, and even collapse can occur as the cat’s lack of oxygen worsens. Without rapid treatment, an asthma attack can be fatal.
Initially, clinical signs might be very subtle, since cats will at first compensate for their decreased respiratory function by reducing their physical activity. In some cases, clinical signs are not readily noticed until the cat has severe difficulty breathing.
Feline asthma can cause severe respiratory difficulties which can lead to open-mouth breathing.
Diagnosis
Unfortunately, there is no one test that can be used to make a clear diagnosis of feline asthma. Putting together the history and clinical signs with the results of several tests will allow your veterinarian to exclude other causes, which may then result in a presumptive diagnosis of feline asthma.
In order to reach a diagnosis of feline asthma, your veterinarian will perform a complete physical exam, which will include listening closely to your cat’s lungs with a stethoscope. X-rays of the lungs, a fecal exam, a complete blood count, and a heartworm test, are also commonly used to aid in the diagnosis. More extensive testing may include tracheal washes, bronchoalveolarlavage and/or bronchoscopy, which all allow for cells to be collected from the airways and analyzed. Bronchoscopy also allows for a camera to be inserted into the airways, which can help rule out certain masses as the underlying cause of the cat’s respiratory difficulty.
Treatment
In an acute asthma attack, oxygen therapy and injectable glucocorticoids are commonly used, as well as bronchodilators, which may be given by injection, nebulization, or inhaler. If a secondary bacterial infection is present, an antibiotic may also be prescribed.
For chronic therapy of feline asthma, bronchodilators and/or glucocorticoids may be given orally or by inhaler. In some cases, such as when a cat will not tolerate oral or inhaled medication, long-lasting glucocorticoid injections may be given. Some cats may only need intermittent treatment when their asthma flares up, while others will require treatment every day for the rest of their lives.
Chronic treatment should also include removing or minimizing the cat’s exposure to allergens and irritants likely to trigger the cat’s asthma. This may include no longer allowing smoking or the use of aerosols in the house, and using a dust-free cat litter. A Hepa-type air filter, which can remove many allergens from the environment, is also recommended.
Prognosis
The prognosis for a cat with feline asthma can range from excellent to grave, and depends on the severity and number of their asthmatic episodes, as well as their response to treatment.
Tips
Because fat can restrict normal ventilation of the lungs, weight loss in overweight cats with feline asthma will help them breathe more easily.