Asthma with Bronchitis in Cats
The lower respiratory tract, or lower airways, includes the bronchi, bronchioles, and alveoli. The bronchi begin at the end of the trachea, where they split off into two branches. From there they split off into smaller branches, called the bronchioles. The alveoli are the terminal portion of the lower respiratory tract, within the lungs, where the exchange of oxygen and carbon dioxide takes place.
Bronchitis is the term used to denote inflammation of the bronchi and bronchioles. Chronic bronchitis is a long-standing inflammation of the lower respiratory tract. The condition of asthma includes both sudden (acute) and long-term (chronic) inflammation of the lower airways due to increased sensitivity to various stimuli, including allergens, narrowing of the airways, and an accumulation of specific cells – seen commonly in inflammation and allergic reactions – within these airways. In cats, both acute and chronic inflammation of the lower airways is denoted collectively as feline bronchitis, or feline bronchopulmonary disease (FBD). Chronic inflammation in the lower airways, if left untreated, may leads to fibrosis (excess fibrous tissue in the lungs) and lung atelectasis (a disease in which the lungs are not able to inflate). This disease can occur in cat of any age, but is most common between the ages of 2-8 years.
Symptoms and Types
Due to the acute and chronic nature of this disease, the following symptoms may be seen for variable period of time:
- Difficulty breathing (some cats will breath with an open mouth)
- Poor appetite
- Fast breathing with effort
- Blue discoloration of skin and mucous membranes
- The exact cause of bronchial inflammation is often unknown
- Cigarette smoke, hair sprays, air fresheners, new furniture, and dusty cat litter may initiate an episode
- Parasitic lung infections (lungworm) are also suspected
Your veterinarian will perform a thorough physical exam on your pet, taking into account the background history of symptoms and possible incidents that might have precipitated this condition. You will be asked about your cat’s diet, addition of new furniture into the home, and other related questions. An exact cause for this disease is not known, and finding the initiating factor is often a daunting task. Sometimes, something as simple as a new air-freshener is found to be responsible for a sudden episode of this disease, but often the exact cause will remain elusive. After a detailed physical examination has been conducted, treatment for acute cases is started immediately (see Treatment).
In the meantime, your veterinarian will take blood and urine samples for laboratory testing. These blood tests will help to establish the diagnosis, and also to characterize whether the problem is acute or chronic in nature. Fecal samples will also be taken for laboratory examination to see if parasites are present. Your veterinarian may also take samples for bacterial culture to see if infection is involved. X-ray imaging may help in diagnosing the nature, extent, and type of changes in the lung parenchyma (the functional parts of the lung) due to inflammation.
At some hospitals, specific allergy testing facilities are available to find which type of allergen is involved, if any. There are also some specific tests that can be used to take samples from the lungs, which can reveal detailed information about the disease.