Usefulness of aerobic microbial culture and cytologic evaluation of corneal specimens in the diagnosis of infectious ulcerative keratitis in animals

Objective-To determine the diagnostic value of aerobic microbial culture an d cytologic evaluation of corneal specimens in the diagnosis of infectious ulcerative keratitis (IUK). Design-Prospective study. Animals-48 animals (26 dogs, 13 horses, 7 cats, 1 bird, and 1 llama) with c orneal ulcers. Procedure-Scrapings from corneal ulcers were examined cytologically. Cornea l swab specimens were submitted for microbial culture. Animals were grouped according to whether they had been receiving antimicrobials at the time of admission. Results-Of the 38 animals receiving antimicrobials, 19 had positive results for IUK on cytologic evaluation, 20 on microbial culture, and 26 on cytolo gic evaluation, microbial culture, or both. Of the 10 animals not receiving antimicrobials at the time of admission, 7 had positive results for IUK on cytologic evaluation, and 9 had positive results on microbial culture. In this group of 10 animals, additional animals with IUK were not identified o n the basis of cytologic evaluation alone. When all 48 animals were conside red irrespective of antimicrobial treatment, 26 and 29 had positive results for IUK on cytologic evaluation and microbial culture, respectively, where as IUK was confirmed in 35 animals on the basis of cytologic evaluation, mi crobial culture results, or both. Conclusions and Clinical Relevance-Microbial culture and cytologic evaluati on of corneal specimens maximizes identification of IUK, especially in anim als receiving antimicrobial treatment. Because of serious consequences of u ntreated IUK, we recommend that both diagnostic tests be used to tailor tre atment and reduce risk of vision impairment in animals.