What are feline asthma and bronchitis?
Feline asthma affects a fair number of cats and is often associated with bronchitis. Asthma is technically an acute or chronic inflammation of the airways associated with several physiologic 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.
The term 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 and your cat will experience 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.
Are some cats more likely to get asthma?
Asthma and bronchitis are seen most commonly 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 and/or fabric softeners, mold/mildew, and essential oil diffusers.
What are the signs of asthma and bronchitis?
Coughing and respiratory distress including difficulty breathing, shortness of breath, and open-mouth breathing are the most common signs of feline asthma and bronchitis. Coughing is a significant finding since there are relatively few causes of coughing in cats. Your cat may assume a squatting position with the neck extended when 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?
Diagnosing asthma and bronchitis in cats requires ruling out other diseases that cause respiratory signs. These diseases include infectious pneumonia (fungal, bacterial, or parasitic), feline heartworm disease, primary lung parasites, and cancer (either a lung tumor or one that has metastasized to the lungs from elsewhere in the body). Diagnostic tests will include a complete blood count (CBC), blood chemistries, fecal exam, and urinalysis. These tests will assess the general health of your cat and may provide clues as to 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, looking for evidence of lungworms.
"Diagnosing asthma and bronchitis in cats requires ruling out other diseases..."
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.
Thoracic radiograph (chest X-ray). There are several characteristic changes seen on lung radiographs in cats with asthma and bronchitis. Radiographs can help eliminate other lung and heart diseases. For instance, feline heartworm and lungworm create specific suggestive lesions that can be seen on radiographs.
Bronchoscopy with cytology and/or culture. Bronchoscopy is a procedure typically performed by a specialist and allows the veterinarian to visualize 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 and for culture.
Tracheal or bronchoalveolar lavage. 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 for microorganisms 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 to stabilize the condition may be required.
"Most cats with asthma and bronchitis are treated as outpatients."
Successful management of feline asthma and bronchitis typically involves some combination of the following:
Avoiding triggers. Any triggers that aggravate breathing problems in cats with this diagnosis should be avoided. This means trying low-dust cat litter, eliminating cigarette smoke from the home, minimizing any dust buildup, using air filters/purifiers, etc. 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, as well as increasing the workload on the heart and lungs. Improving body condition is critical to success.
Bronchodilators. Bronchodilators are 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 to be effective, they need to be used consistently, as directed by your veterinarian.
Corticosteroids. Corticosteroids have potent anti-inflammatory effects and can provide relief to cats experiencing the respiratory distress of asthma and bronchitis. A cat may receive an injection of a long-acting corticosteroid (such as Depo-Medrol®) that has the ability to relieve symptoms for several weeks to several months. More commonly, a cat may be prescribed a short course of oral corticosteroids combined with an inhaled corticosteroid, such as fluticasone (Flovent®), to limit the effects of the steroid on the lungs and minimize negative side effects. There is also a combination bronchodilator-corticosteroid combining fluticasone and the bronchodilator salmeterol (Advair®) in the same inhaler.
Hypoallergenic nutrient profile. Your cat may benefit from a diet that is either less allergenic or truly hypoallergenic. Nutrition takes time to have its effect on cats with asthma and bronchitis but may lower the reliance on medication.
Medical acupuncture. Neuromodulation via medical acupuncture is a technique that can provide relief to some cats with asthma and bronchitis. In those cats who respond to medical acupuncture, the reliance on medication may be reduced.
See the handout "Treatment Instructions for Asthma and Bronchitis in Cats" for more information on treatment.
Will my cat be cured of asthma and bronchitis?
Treatment of this disease syndrome is considered management, as a cure rarely occurs. Cats with feline asthma and bronchitis are rarely cured. The goal of treatment is to lessen the severity and frequency of the attacks and improve the overall quality of life. Most cats with feline asthma and bronchitis can live very full and active lives.