Pneumonia, Bacterial

Home , Bacterial pneumonia, Lobar pneumonia

Ronald M. Bright, DVM, MS, DACVS

BASIC INFORMATION the cause. Culturing of the secretions usually demonstrates bacte- Description ria. Bronchoscopy, which involves passage of a fiberoptic scope Bacterial pneumonia is inflammation of the lungs that is caused by into the airway, may help eliminate parasites, foreign bodies, or associated with a bacterial infection. When a single lung lobe is other forms of pneumonia, and tumors as potential causes. Lung involved, it is referred to as lobar pneumonia . Bronchopneumonia biopsies are rarely done but are sometimes considered. is inflammation of both the lower airways (bronchi) and the lungs. Other tests may be recommended to rule out other diseases that Causes can cause coughing and similar x-ray changes, and to search for an Most cases of bacterial pneumonia develop secondary to some underlying or contributing cause. other underlying disease or condition: • Bronchitis can progress to pneumonia. TREATMENT AND FOLLOW-UP • Some congenital diseases (such as ciliary dyskinesia) predis- pose dogs of certain breeds to pneumonia, but these are rare. Treatment Options • Cases of viral or fungal pneumonia may develop secondary Antibiotics are the primary therapy and are usually chosen based bacterial infections. on results of bacterial culture and antibiotic sensitivity testing. • Areas of aspiration pneumonia may become infected. Oxygen supplementation is warranted for more severe cases. • Penetrating foreign bodies in the lung may introduce bacteria. Bronchodilators sometimes help improve breathing problems. • Drug therapy and certain diseases (diabetes mellitus, adrenal Keeping the animal well hydrated with fluid therapy and gland hyperfunction) that suppress an animal’s natural immune humidifying the environment are often helpful. Affected animals system make it vulnerable to bacterial pneumonia. may also benefit from frequent walks to prevent them from lying • Animals that lie on their side for prolonged periods because of in one position for long periods. Chest coupage, which is gentle some disease process or anesthesia are predisposed to partial col- but forceful thumping on the rib cage, may help loosen secretions lapse of the lungs, and these areas can then become infected. in the respiratory tract. • Trauma and cancer of the lungs can be followed by bacterial An important goal of therapy is to identify any predisposing invasion. conditions and correct them. In some cases, lung changes become so severe and chronic that surgical removal of the diseased lung Clinical Signs is necessary. A productive cough (coughing up phlegm) and nasal discharge are common signs. Rate and effort of breathing may be increased, and Follow-up Care wheezing may be heard. The animal may be lethargic and unable Intensive, continuous monitoring of respiratory function is usually to exercise. Fever, weight loss, and decreased appetite may occur. needed while the animal is hospitalized. Repeated chest x-rays are an excellent way to evaluate response to therapy and are usually Diagnostic Tests done every 24-48 hours. After the animal is stable and discharged Be sure to give your veterinarian details as to travel history, prior from the hospital, chest x-rays are often taken again in 5-7 days. illnesses, and prior vaccinations of your pet, because they may Laboratory tests may be performed every few days to monitor provide insight into the possible causes of pneumonia. For exam- changes caused by inflammation and infection. ple, a history of chronic airway disease, regurgitation, or a recent Notify your veterinarian if signs persist or worsen, because fail- anesthetic event may be important in solving the diagnosis. Certain ure to improve on therapy may indicate the need to change anti- characteristic lung sounds (crackles) and sometimes an expiratory biotics or the development of complications such as a lung lobe (while breathing out) wheeze may be heard with a stethoscope on abscess, spread of the infection to other parts of the body (sepsis), physical examination. or irreversible lung lobe changes. Failure to improve also may be Routine laboratory tests and chest x-rays are often recom- a sign that an underlying cause (such as regurgitation or diabetes) mended to investigate potential causes of a cough or respiratory is not being effectively managed. distress. Chest x-rays may show lungs changes consistent with Prognosis bacterial pneumonia. Animals in severe distress may require ther- Most cases of bacterial pneumonia resolve with appropriate use of apy before other tests are performed. antibiotics, assuming that the underlying cause is also successfully In animals that are stable, analysis of secretions taken from managed. Unresponsive animals may become systemically ill and the trachea and bronchi by transtracheal wash may help confirm may not respond even to intensive therapy in the hospital.