Current Strategies for Treating Pleural and Peritoneal Infections

Pyothorax and septic peritonitis are a life threatening condition in dogs and cats that causes serious metabolic alterations and organ dysfunction. They result from contamination of the pleural or peritoneal space by microorganisms. Pyothorax and septic peritonitis will result in septic shock and death of the patient if not treated appropriately.

Treatments of pyothorax and peritonitis have 3 goals: administer appropriate supportive medical treatment (antibiotics, fluid therapy, shock therapy), lavage thoroughly the pleural and the peritoneal cavity with sterile warm saline to flush bacteria or debris, and surgical correction of the primary problem if possible.

Medical Treatment
Antibiotic therapy is initiated as soon as the diagnosis is established and samples are collected for culture and sensitivity. Cytology of the pleural fluid may show presence of filamentous organisms indicative of Actynomyces or Nocardia. Combination of Ampicillin (20 mg/kg three times a day) and Enrofloxacin (5 mg/kg 2 times a day) is appropriate while waiting for result of a culture and sensitivity. Cefoxitin (22 mg/kg IV three times a day) is also a good choice. If filamentous organisms are visible Clindamycin is then indicated. Presence of filamentous organisms is an indication that plant material is present.

Since the goal of medical treatment is to optimize oxygen delivery it is paramount to measure lactate level. Elevate lactate level is an indication of anaerobic metabolism, and poor oxygen delivery. Since oxygen delivery is a function of cardiac output and oxygen content, it is important to optimize cardiac function, pulmonary function and hemoglobin level.  [...]