Asthma and Bronchitis in Cats

What are feline asthma and bronchitis?

Feline asthma is somewhat common in cats and is often associated with bronchitis. Asthma is technically an acute or chronic inflammation of the airways. It is associated with several physiological effects, including increased responsiveness to various noxious stimuli, narrowing (constriction) of the airways, reversibility of airway constriction, and the presence of inflammatory cells within the airways.

Feline bronchitis describes the coughing and/or wheezing that comes from inflammation in the lower airway. Asthma and bronchitis are typically considered two parts of the same syndrome. This syndrome may also be referred to as chronic obstructive pulmonary disease (COPD).

If your cat's airways are sensitive to certain stimuli, exposure to those agents can cause an inflammatory response, causing your cat to have bronchial (airway) spasms, increased mucus production, and possible accumulation of mucus in the airways. The inability to clear the bronchi of mucus can lead to airway obstruction and can result in secondary respiratory infections. Chronic airway obstruction may trap air in the tiny air sacs of the lungs called alveoli, leading to over-inflation and lung damage, and possibly lung lobe collapse.

Are some cats more likely to get asthma?

Asthma and bronchitis are most common in cats two to eight years of age, and Siamese cats seem to be at higher risk. Overweight and obese cats are also at greater risk for developing chronic respiratory disease. Dental disease increases the risk that bacteria will travel from the mouth into the lungs and cause a serious secondary infection.

What causes feline asthma and bronchitis?

The cause of the inflammation associated with feline asthma and bronchitis is unknown. It is better to consider triggers that enhance the inflammation and cause asthma and bronchitis signs. These triggers may include dust from cat litter, cigarette smoke, perfume, hairspray, carpet cleaners, air fresheners, scented laundry detergent, scented fabric softeners, mold, mildew, pollens, pollution, and essential oil diffusers.

What are the signs of asthma and bronchitis?

The most common signs of feline asthma and bronchitis are coughing and respiratory distress, including difficulty breathing, shortness of breath, and open-mouth breathing. Coughing is a significant finding, since there are relatively few causes of coughing in cats.

When your cat coughs, it may assume a squatting position with its neck extended. The cough is usually “dry” or harsh, and the cat will commonly gag after coughing. Some owners mistakenly think their cat is vomiting or trying to pass a hairball, when in fact it is coughing. Your cat may also wheeze, sometimes loud enough to hear if you are close by.

As the disease progresses, your cat may appear to have less energy and may have difficulty breathing. Breathing may become noisy, and your cat may wheeze when exhaling. In later stages, the gums may develop a bluish tinge due to a lack of oxygen. Cats with asthma or chronic bronchitis rarely have a fever and their appetite usually remains normal.

How is asthma diagnosed?

To diagnose asthma and bronchitis in cats, your veterinarian must rule out other diseases that cause respiratory signs. These diseases include infectious pneumonia (fungal, bacterial, or parasitic), feline heartworm disease, primary lung parasites, and cancer (a lung tumor or tumor that has spread to the lungs).

Diagnostic tests include a complete blood count (CBC), blood chemistry, fecal exam, and urinalysis. These tests assess the general health of your cat and may provide clues about the underlying cause. One type of white blood cell, the eosinophil, is commonly associated with allergic events or parasitic disease, and its presence supports a tentative diagnosis of asthma. Elevated blood proteins also occur in some affected cats. In some cases, special tests will be performed on stool samples, to look for evidence of lungworms.

Additional diagnostic tests may include:

• Heartworm test. This blood test should be performed on any coughing cat and is often performed in conjunction with feline leukemia (FeLV) and feline immunodeficiency virus (FIV) tests.
• Chest X-rays. Several characteristic changes can be seen on lung X-rays in cats with asthma and bronchitis. X-rays can also help eliminate other lung and heart diseases. For instance, feline heartworm and lungworm create specific patterns that can be seen on X-ray.
• Bronchoscopy with cytology and/or culture. Bronchoscopy is a procedure typically performed by a specialist that allows the veterinarian to see the airways of an anesthetized cat with a small fiber-optic scope. Samples of the mucus and cells lining the bronchi may be obtained for examination under the microscope (cytology) and cultured for microorganisms such as bacteria and fungi.
• Tracheal or bronchoalveolar lavage. In this procedure, the cat is usually placed under sedation or anesthesia and a thin, flexible, sterile catheter is passed into the area being investigated. A small amount of sterile fluid is flushed forcefully into the area and then promptly suctioned or aspirated back out. The recovered fluid contains mucus and a small number of cells that can be cultured and examined under the microscope.

In most cases, a single underlying cause cannot be identified, despite a thorough diagnostic work-up.

How is asthma treated?

Most cats with asthma and bronchitis are treated as outpatients. If your cat is experiencing severe respiratory distress, hospitalization for oxygen therapy and/or intravenous medication may be required to stabilize the condition. Successful management of feline asthma and bronchitis typically involves some combination of the following:

Avoiding triggers. Cats with asthma should avoid any triggers that aggravate breathing problems. You may need to try a variety of measures, including low-dust cat litter, eliminating cigarette smoke from the home, minimizing dust buildup, and using air filters/purifiers. It is important to pay close attention to environmental factors that may aggravate or worsen your cat’s condition.

Improving body condition. Being overweight or obese causes systemic inflammation that can contribute to feline asthma and bronchitis, and also increase the workload on the heart and lungs. Improving body condition is critical to success.

Bronchodilators. Bronchodilators are medications used to open the airways, allowing your cat to move air in and out of the lungs more freely. They are usually administered in an inhaled form, such as albuterol/salbutamol (Ventolin®). For this treatment to be effective, the medication must be used consistently, as directed by your veterinarian.

Corticosteroids. Corticosteroids are drugs with potent anti-inflammatory effects that can provide relief to cats experiencing respiratory distress. Typically, a cat is prescribed a short course of oral corticosteroids, combined with an inhaled corticosteroid, such as fluticasone (Flovent®), to limit the effects of the steroid to the lungs and minimize negative side effects.

There is also a combination bronchodilator-corticosteroid that combines fluticasone and the salmeterol (Advair®) in the same inhaler. Less commonly, a cat may receive an injection of a long-acting corticosteroid (such as DepoMedrol®) that can relieve symptoms for several weeks to months. However, this treatment may be associated with more negative side effects.

Hypoallergenic nutrient profile. Your cat may benefit from a diet that is either less allergenic or truly hypoallergenic. Nutrition takes time to affect cats with asthma and bronchitis but may lower the reliance on medication.

Medical acupuncture. Neuromodulation through medical acupuncture is a technique that may provide relief to some cats with asthma and bronchitis. In those cats that respond to medical acupuncture, the reliance on medication may be reduced.

What is the prognosis for a cat with asthma and bronchitis?

Cats with feline asthma and bronchitis are rarely cured. Treatment is aimed at managing the disease. The goal of treatment is to lessen the severity and frequency of attacks and to improve the overall quality of the cat’s life. Most cats with feline asthma and bronchitis can live full and active lives.