TOPICAL TREATMENT OF PSEUDOMONAS SP-INFECTED CORNEAL ULCERS IN HORSES- 70 CASES (1977-1994)

Objective-To determine which antimicrobial agents were most effective against Pseudomonas sp-infected ulcerative keratitis, and identify any trends in the various clinical conditions associated with these bacte ria that might assist in effective treatment of the disease. Design-Re trospective case series. Animals-66 horses with 70 Pseudomonas sp-infe cted corneal ulcers. Procedure-We reviewed medical records of horses a dmitted to the George D. Widener Hospital for Large Animals, Universit y of Pennsylvania between July 1977 and December 1994. Records of hors es that had Pseudomonas sp isolated from a corneal ulcer scraping or d eep swab were included in the study. Results-Aggressive topical medica l treatment was successful in 57 ulcers and most likely would have bee n effective in 5 additional ulcers. Antimicrobial susceptibility testi ng indicated susceptibilities of 87, 85, and 93% to tobramycin, gentam icin, and amikacin, respectively, Although concurrent fungal infection s were identified in only 2 of 35 ulcers examined, almost three fourth s of the ulcers were treated with antifungal medications prophylactica lly. Clinical outcomes of the 70 affected eyes included: excellent vis ion with minimal leukoma, 73%; enucleation, 19%, blind phthisical eye, 4%; peripheral vision only, 3%; and euthanasia of newborn, 1%. Clinic al Implications-Aggressive topical medication with microbial agents ef fective against Pseudomonas sp-can result in excellent vision with min imal leukoma in most horses with corneal ulcers.