Chronic Unilateral Ophthalmitis Caused by Klebsiella pneumoniae complex in a Cockatiel (Nymphicus hollandicus): A Case Report

Background: The cockatiel (Nymphicus hollandicus), an Australian psittacine species, is widely appreciated as a companion animal and serves as a key model organism for scientific research. However, these birds are vulnerable to various pathogens. While the pathology of these common diseases is extensively reported, clinical literature on infections by opportunistic or uncommon pathogens presenting with atypical manifestations remains limited. This case report contributes to this area by detailing a rare presentation of chronic unilateral ophthalmitis caused by Klebsiella pneumoniae complex, thereby expanding the documented scope of pathologies affecting this species. Methods: A cockatiel with a six month history of unilateral ophthalmic inflammation was referred to the Small Animal Hospital, University of Tehran. The bird exhibited lethargy, reduced appetite, periocular scaling, and a fleshy granular mass around the affected eye. The ophthalmic lesion had been refractory to previous empirical treatments. During the clinical evaluation, an aseptic conjunctival and periocular sample was collected using a sterile swab from the affected eye. The specimen was cultured on blood agar and MacConkey agar plates and incubated overnight at ۳۷ °C. Results: Microbiological examination of the resulting colonies identified Klebsiella pneumoniae complex consistent with the clinical examination. Topical ophthalmic therapy with chloramphenicol and Fluticasone eye drop was also prescribed. After ۷ days of treatment, significant clinical improvement was observed, with reduced periocular scaling and resolution of the ophthalmic lesion. The bird regained normal appetite and activity levels, and a follow-up examination confirmed the absence of infection. Conclusion: This case report establishes Klebsiella pneumoniae complex as a significant pathogen capable of causing chronic, granular ophthalmitis in cockatiels. The findings underscore the necessity of including opportunistic bacteria in the differential diagnosis of persistent avian ocular lesions, particularly when initial empirical treatments fail.

کلیدواژه ها:

Cockatiel ، Chronic Ophthalmitis ، Klebsiella ، Bacterial infection