Probable transmission of Chlamydia psittaci from a macaw to a cat

A 5-year-old Siamese cat developed unilateral mucopurulent ocular discharge and conjunctivitis 1 month after the introduction of a macaw into the household. Despite treatment with antimicrobial ophthalmic ointment, the conjunctivitis became bilateral and other systemic signs developed. Intracellular inclusions consistent with a Chlamydia psittaci infection were detected in conjunctival epithelial cells stained with a fluorescein-labeled monoclonal antibody. Chlamydia psittaci was isolated from samples obtained by conjunctival scraping. Subsequently, C psittaci was recovered in samples obtained from the feces of the bird. The cat and the bird were successfully treated with doxycycline. Historic and epidemiologic findings supported the theory of orthozoonotic transmission of C psittaci from the bird to the cat.