Chest and Lung Conditions

The lungs can be affected by infections and injuries. They may also be affected by heart conditions. Some allergies may show up as chest complaints. Certain infections destroy large areas of lung tissue; these tissues cannot be regenerated, and heal to form fibrous scar tissue, which is unable to perform respiratory functions.

Acute Bronchitis

Infection with a kennel cough (canine cough) complex of microorganisms, or irritation from air pollution or allergies, can trigger a bout of coughing that is associated with inflammation of the bronchi. This condition is called acute bronchitis. An affected dog has a harsh, dry cough but otherwise appears well.

Diagnosis & Treatment of Acute Bronchitis

Diagnosis is based on the dog's medical history and the clinical signs. Diagnostic tests are seldom necessary for simple acute bronchitis. Treatment is the same as for in infectious cough.

Chronic Bronchitis

A cough that persists for more than eight weeks has become chronic. Such coughing is rarely caused by infection, although infection may precede its development. It is actually due to a persistent inflammation of the bronchi; the condition is called chronic bronchitis or, more accurately, chronic obstructive pulmonary disease (COPD).

COPD usually affects middle-aged and older dogs. Although an exact cause is rarely discovered, pollutants and allergens are usually implicated. The disorder is fairly common in west Highland White terriers, a breed that has a known risk of developing allergic skin conditions.

Coughing may be triggered by exercise or excitement and is worst at night. The coughing is dry and harsh and may end with gagging and retching of foamy saliva, which is often mistaken for vomiting. In all other respects, an affected dog appears normal.

Diagnosis
X-rays of a dog with COPD reveal thickening of the bronchi and possibly emphysema (rupture of the air sacs in the lungs), although mild emphysema is not visible on X-rays. Bronchoscopy and bronchial washes may be performed to check for any infected debris in the airways.

Treatment of Chronic Bronchitis

Initial management may include a short course of corticosteroid drugs to reduce inflammation. If these produce a dramatic improvement, the dose is reduced, with the vet aiming at low-dose alternate-day treatment. Bronchodilators are used to ease the dog's breathing, while cough medicines containing codeine are given to reduce the tickle of the cough.

Pneumonia

Pneumonia, also called pneumonitis, is inflammation of the lungs due to bacterial, viral, or fungal infections. Pneumonia often occurs as a secondary infection that has spread from the upper respiratory tract. It is uncommon in healthy dogs, occurring most frequently in very young or very old animals, or those with impaired immune system. In addition, individuals with chronic bronchitis or a collapsing trachea are more susceptible than normal.

Aspiration pneumonia occurs when food or fluid gets into the lungs—for example, as a result of an impairment of the dog's swallowing mechanism or during general anesthesia. Inhalation of smoke or noxious chemicals may also lead to pneumonia.

An individual with pneumonia is depressed, feverish, and breathes fast. There is often a moist-sounding bubbly cough. If the pneumonia is severe, the affected dog may sit or stand with its head extended to make its breathing easier.

Treatment of Pneumonia

Diagnosis is made by chest X-ray and blood tests. Treatment with antibiotics begins immediately and continues for at least three weeks, until X-rays show that the lungs are beginning to heal. Some dogs need to be hospitalized in an oxygen-enriched kennel. Nonsteroidal anti-inflammatory drugs (NSAIDs) may be used to relieve discomfort. Cough suppressants, however, are never given; coughing is beneficial in pneumonia because it helps to clear blocked air passages and mucus.

Pleurisy

Pleurisy, also called pleuritis, is inflammation of the chest (pleural) cavity. The condition usually occurs in conjunction with pneumonia. An affected breathes shallowly, has a fever, and shows signs of pain if it is touched on the chest.

Diagnosis & Treatment of Pleurisy

If your dog has pleurisy, the vet will hear friction sounds when listening to the chest with a stethoscope. Treatment includes appropriate medication to eliminate infection and provide pain control.

Fluid Around the Lungs

An accumulation of any fluid between the pleura (the two membranes that cover the lungs and the chest cavity) is known as pleural effusion.

Trauma, tumors and spontaneous bleeding disorders may all cause blood to build up in the chest (a condition called hemothorax). Much more commonly, a serum-like fluid, called transudate, may accumulate in the area as a consequence of heart failure. Fluid may also build up as a result of liver or kidney disease, or tumors that have spread to the lungs from elsewhere in the body. In some situations, pleurisy produces pus that collects in the chest cavity.

Whatever the fluid involved, an affected dog finds it increasingly difficult to breathe, and may stand with its head and neck extended, taking short, rapid, labored breaths. The lips and gums may turn blue (a sign called cyanosis).

Diagnosis & Treatment

X-rays reveal a characteristic "ground glass" appearance due to the presence of fluid around the lungs.

Urgent treatment is needed. Using either a catheter or a needle, the vet will drain the fluid from around the lungs. The procedure is also usually diagnostic, because the type of fluid that has accumulated in the chest cavity will indicate to the vet the cause of the fluid buildup.