When inflammation strikes actual tissue within the lungs themselves, a condition of pneumonia is said to exist. Pneumonia doesn’t necessarily mean that an infection is present; on the contrary, there are a number of noninfectious causes of pneumonia that need to be considered whenever a dog or cat is showing signs of lung disease. For instance, aspiration pneumonia can result from the accidental inhalation of a substance originally destined for the stomach. Dogs and cats suffering from seizures, persistent vomiting, or structural abnormalities, such as megaesophagus or cleft palate, are very susceptible to this type of pneumonia. Pneumonia can also result from inhalation of smoke and certain caustic chemicals. The damage caused by these noninfectious sources is often so severe that the unfortunate victims develop bacterial pneumonia as a secondary problem.
Pets suffering from pneumonia will cough incessantly and often spit up mucus and phlegm. Obvious breathing difficulties are noticed in severe cases, with a reluctance by the pet to move or exert itself. Dogs so affected might stand with their front legs spread wide apart and their necks lowered and extended to afford the passage of more air into the lungs. Fever, lethargy, and loss of appetite are also seen in patients with pneumonia.
Clinical signs combined with abnormal lung sounds detected with a stethoscope can lead a veterinarian to suspect a case of pneumonia. Chest radiographs are needed to confirm such suspicions. If a bacterial or fungal component is thought to exist, a culture of the fluid and mucus within the respiratory tree might be performed as well.
Blood work will usually show an elevated white blood cell count. With infectious pneumonia, high doses of appropriate antibiotics and/or antifungal medications will be required to bring it under control. Drugs designed to expand the airways are helpful in improving airflow into and out of the lungs. Intravenous fluids are also useful to replace important body fluids lost in the increased respiratory secretions and to prevent existing secretions from becoming thickened as a result of dehydration. (Note: Medications designed to suppress coughing should not be used in most cases, since this only serves to prevent the removal of mucus and other respiratory secretions from the lungs.)
Cases of aspiration or inhalation pneumonia are treated in a similar fashion, yet these carry a much poorer prognosis. Attempts to suction the foreign material out of the lungs through the trachea are often unsuccessful. Pets that survive are often afflicted with a residual cough for the rest of their lives.
Chronic Obstructive Pulmonary Disease (COPD)
Chronic obstructive pulmonary disease (COPD) is a disorder of the lungs and respiratory tree often linked to aging. It is seen primarily in dogs. COPD is actually a catch-all phrase for all those conditions that affect and restrict normal air movement into and within the lungs. Chronic bronchitis and age-related scarring of the actual lung tissue are the two most common causes of COPD in canines.
COPD is characterized by persistent coughing, mucus buildup within the airways, and breathing difficulties. Definitive diagnosis of chronic obstructive pulmonary disease can be made by ruling out other potential causes of clinical signs (pneumonia, canine cough, etc.), evaluating the duration of the clinical signs, and obtaining biopsy samples of lung tissue to determine whether scar tissue is indeed present.
Unfortunately, if diagnosed, there is no treatment presently available that can reverse the effects of COPD. However, medications designed to dilate the airway passages can provide some degree of respiratory relief to the affected pet. In addition, anti-inflammatory medications can also be utilized to reduce inflammation and slow scar tissue formation that may be contributing to the COPD.