Chronic Bronchitis in Cats

What is chronic bronchitis in cats?

Chronic bronchitis is a long-term inflammatory condition that affects the pulmonary or respiratory system. It is progressive and irreversible.

What causes chronic bronchitis?

There are no definitive underlying causes of chronic bronchitis. However, long-term airway inflammation may result from exposure to inhaled irritants such as tobacco smoke, air pollutants, or allergens. Dental disease or recurrent infections of the respiratory system may also be underlying causes of chronic bronchitis. The terms “feline asthma” and “allergic airway disease” are often used interchangeably with chronic bronchitis.

Are there other health factors that can make chronic bronchitis worse?

Yes, obesity is a complicating factor and will worsen symptoms of bronchitis. Dental disease also increases the risk of bronchitis, because bacteria can travel from the mouth into the lungs and cause a serious secondary infection.

What part of the respiratory system is involved in chronic bronchitis?

The respiratory system is divided into two parts. The upper respiratory tract consists of the nose, nasal sinuses, throat, and trachea or windpipe, while the lower respiratory tract consists of the “small airways” (bronchi and bronchioles) and alveoli (small air sacs deep in the lung tissue where oxygen exchange occurs). Chronic bronchitis is a condition of the lower respiratory tract. Initially it affects the small airways, although in advanced cases, it will progress and affect the alveoli.

How does chronic bronchitis affect a cat’s lungs?

In its early stages, chronic bronchitis causes inflammation in the small airways. Persistent inflammation causes blockage of the small airways and will ultimately result in reactive changes in the lungs, including dilation in parts of the small airways (bronchiectasis), scarring in the lungs (pulmonary fibrosis), and lung lobe collapse.

How fast do these changes occur?

This condition develops slowly and progressively.

Does it affect all breeds and ages of cats?

Chronic bronchitis most often affects middle-aged and older cats. There is some evidence to suggest that Siamese cats may be at higher risk of developing this condition.

What are the symptoms of chronic bronchitis?

In its early stages, the main symptom of chronic bronchitis is constant coughing, or coughing that persists for longer than a month. The cough is usually “dry” or harsh, and gagging is common after coughing (some owners mistakenly think their cat is vomiting or trying to pass a hairball when in fact it is coughing).

As the disease progresses, the cat may appear to have less energy and may have difficulty breathing. Breathing may become noisy, and a cat may wheeze when exhaling. In later stages, the gums may develop a bluish tinge due to a lack of oxygen.

When at rest, the cat’s breathing rate is faster than normal. With some practice, counting your cat’s breathing rate (number of breaths per minute) is something you can routinely do at home. Cats with chronic bronchitis rarely have a fever and usually their appetite remains normal.

Could these symptoms be caused by something else?

Chronic coughing may also be a symptom of a lung infection or some types of cancer. Coughing is a common symptom of heart disease in people and dogs, but is not usually a symptom of heart disease in cats.

How is chronic bronchitis diagnosed?

Your veterinarian may suspect chronic bronchitis based on your pet’s history and the results of a physical examination. When they listen to the chest with a stethoscope, your veterinarian may hear “crackles” (harsh crackling or popping sounds) when the cat breathes in and out. With chronic bronchitis, the heart rate is usually normal or lower than normal.

To rule out other diseases, it is important for your veterinarian to take a thorough medical history, documenting the onset of the problem and its progression, any changes in the cat’s home environment, and any other signs of illness in the cat. Diagnostic tests may include blood tests, X-rays, a bronchoscopy exam (which involves a small camera down your cat’s airways), or tracheal washing.

Samples collected by a bronchoscopy or tracheal washing will be submitted for laboratory testing such as cytology (microscopic examination of cells), histology (microscopic examination of tissue samples), or bacterial identification and culture. A cat will usually require sedation or anesthesia for some of these procedures.

What is the treatment for chronic bronchitis?

Most cats with chronic bronchitis are treated as outpatients. If the cat is experiencing severe respiratory distress, hospitalization for oxygen therapy and/or intravenous medication to stabilize the condition may be required.

Specific medications that may be prescribed include bronchodilators to dilate the airways and help clear secretions, cough suppressants, antibiotics if there is evidence of a secondary bacterial infection, and corticosteroids to decrease the inflammation. Some of these medications can be provided as inhalers given with a special chamber placed over your cat’s nose and mouth. Avoidance of irritants such as smoke or airborne allergens will help lessen the chance of relapses.

Newer therapies for chronic bronchitis include stem cell therapy and desensitization with allergen-specific immunotherapy (“allergy shots”). Non-specific treatments for chronic bronchitis may include diet modification to promote weight loss in an overweight cat. Your veterinarian may prescribe supplements that have antioxidant, anti-inflammatory or immune stimulant functions as supportive treatments.

It is important to maintain good oral health in a cat with chronic bronchitis. Daily toothbrushing is extremely beneficial. Regular dental descaling, cleaning, and polishing under general anesthesia is strongly recommended to minimize the chance that bacteria from the mouth will cause a secondary infection in the inflamed respiratory tract.

What is the success rate for treatment of chronic bronchitis?

This condition is non-reversible and often slowly progressive. Appropriate treatment will slow the progression of the disease and relieve distressing symptoms. With proper management, most cats with chronic bronchitis enjoy a normal life expectancy and an excellent quality of life. Relapses may occur when the seasons change or if air quality is poor. Adjustments to medication dosages may be necessary at these times. Consult your veterinary clinic for specific advice.