Abstract
BACKGROUND: Klebsiella pneumoniae can cause high mortality in birds. In recent years, small farming of canaries has been developed in Iran and infectious diseases are the main obstacle in the progress of these occupations which increases the importance of identification of pathogenic bacterial agents. CASE DESCRIPTION: A flock with 250 one-year-old canaries presented a history of anorexia, lethargy, mild diarrhea, and approximately 30% mortality. Physical examination revealed that the birds were severely debilitated, cachectic, dehydrated with ruffled feathers, and wet discolored stool around the cloaca. Necropsy findings revealed enlarged liver with multiple pale white, irregular foci on the surface of parenchyma, serosal petechial hemorrhages, and enlargement of lungs, liver, and kidneys. The entire intestine was intensely reddened with fibrinonecrotic exudate content. Histopathological findings of the liver elicited multifocal hepatocellular necrosis, hemorrhage, and also basophilic bacterial colonies. The results of biochemical and molecular tests confirmed K. pneumonia as the causative agent. FINDINGS/TREATMENT AND OUTCOME: Based on antimicrobial susceptibility test, K. pneumonia isolates were susceptible to gentamycin and ciprofloxacin which were administrated for the considered treatment protocol. CONCLUSION: K. pneumoniae is one of the most important causes of mortality in canaries with multiple antibiotic resistance, therefore assessments of health conditions can supply suitable information to help decision-making about the sanitary processes, control, prevention, and treatment.