It is usually only when your pet has a chronic cough or one not responding to treatment that we undertake a full diagnostic work-up. This includes x-rays, a stool sample for lungworm and other eggs and bronchoscopy, especially when there is mucus and blood. A bronchoscope allows us to look inside the windpipe and bronchi and to collect biopsy samples or washings for examination under the microscope. Tracheal flushes can be performed without a bronchoscope by flushing sterile saline into the windpipe of a sedated or anaesthetised pet. Cells in the wash are examined by a cytologist while other portions of the sample are retained for bacterial culture. This is an excellent diagnostic tool leading to accurate diagnoses.
Chronic Bronchitis Or Chronic Obstructive Pulmonary Disease (COPD)
A cough that persists for over eight weeks has become chronic. It is rarely caused by infection, although infection may precede its development. The cough is caused by a persistent inflammation to the bronchi and is called either chronic bronchitis or more accurately chronic obstructive pulmonary disease (COPD). COPD usually affects middle aged and older individuals. Although an exact cause is rarely discovered, pollutants and allergens are usually implicated. COPD is not uncommon in West Highland White Terriers and Siamese cats.
In dogs, coughing may be triggered by exercise or excitement and is worst at night. The cough is dry and harsh and may end with gagging and retching foamy saliva, often mistaken for vomiting. In all other aspects an affected dog appears normal.
Diagnosis and treatment
X-rays reveal thickening of the bronchi and possibly rupture of the air sacs (emphysema) although very mild emphysema is not visible on x-rays. Bronchoscopic examination and bronchial washes (lavage) reveal any infected debris. Our initial medical management may include a short course of corticosteroids. If this produces a dramatic improvement the dose is reduced, aiming at low-dose alternate-day treatment. Bronchodilators are used to ease breathing while cough medicines with codeine reduce the tickle of the cough in dogs. Weight loss is beneficial for overweight pets while known atmospheric pollutants and allergens are avoided. Calm exercise is beneficial.