Mycoplasma gallisepticum isolated from house finches (Carpodacus mexicanus) with conjunctivitis.

An epornitic of conjunctivitis in free-flying house finches (Carpodacus mexicanus) occurred in several mid-Atlantic and eastern states of the USA in 1994. Clinical signs and gross lesions ranged from mild to severe unilateral or bilateral conjunctival swelling with serous to mucopurulent drainage and nasal exudate. Microscopic lesions consisted of chronic lymphoplasmacytic conjunctivitis, rhinitis, and sinusitis. Notably slow-growing mycoplasmas were isolated from conjunctival and/or infraorbital sinus swabs from clinically affected birds. Isolates were identified as Mycoplasma gallisepticum (MG) by direct immunofluorescence and DNA probe-based polymerase chain reactions. These findings suggest that MG is the likely etiology for this epornitic of conjunctivitis in house finches.