Presumed clostridial and aerobic bacterial infections of the cornea in two horses.

Microscopic examination of Gram-stained tissue specimens collected from severe corneal ulcers in 2 horses revealed large gram-positive rods suggestive of Clostridium spp. Clostridium perfringens was isolated from specimens collected from horse 1; anaerobic organisms were not detected in specimens from horse 2. Aerobic bacterial culture revealed Aeromonas hydrophila and Enterobacter cloacae in specimens collected from horses 1 and 2, respectively. An insect exoskeleton was presumed to be the underlying cause of ulceration in horse 1. Cause of ulceration in horse 2 was not determined. Antibiotics used to treat the corneal infections included ticarcillin disodium-clavulanic acid injected one time subconjunctivally and chloramphenicol applied topically at frequent intervals. Horse 2 also received penicillin or trimethoprim-sulfadiazine. Small leukomas were the only lesion remaining between 2 and 7 months after initial evaluation. Chloramphenicol applied topically appears to be an effective treatment against clostridial corneal infections in horses.

Evaluation of a commercial automated system and software for the identification of veterinary bacterial isolates.

A commercial gram-negative bacterial autoidentification plate was originally developed using bacterial isolates of human origin. Three veterinary diagnostic laboratories conducted a 2-phase trial to enhance the database for veterinary use. The first phase consisted of testing the plate with 447 bacterial isolates of veterinary origin and incorporating that data into the existing database. Emphasis was placed on the Actinobacillus, Bordetella, Pasteurella and Enterobacteriaceae groups, since the Pseudomonas taxon was quite complete. The second phase of the trial consisted of evaluating the enhanced database using 270 clinical veterinary isolates normally encountered in veterinary laboratories. For the Actinobacillus, Bordetella, Pasteurella and Enterobacteriaceae groups, 72% of the bacterial isolates were identified correctly to genus and 85% to species after 18 hours incubation. All identifications in phase 1 and phase 2 were confirmed using conventional methods.

Embryonic loss in pony mares induced by intrauterine infusion of Candida parapsilosis.

Pony mares which were detected pregnant by transrectal ultrasonography received a single intrauterine infusion of either sterile saline (control, n = 12 mares) or 10(6)Candida parapsilosis (treated, n = 12 mares) between Days 11 to 14 postovulation. Subsequent embryonic loss was studied by daily ultrasonography of the mare's uterus, by serum progesterone levels, by endometrial swabs for cytologic and microbiologic examination and by endometrial biopsies that were taken after embryonic loss was detected. Significantly fewer (P<0.01) embryonic losses occurred in control than in treated mares (4 12 vs 12 12 ). The mean interval from intrauterine infusion until embryonic loss was 5.8 +/- 2.8 d for control mares (n = 4) and 2.1 +/- 0.2 d for treated mares (n = 12). Prior to embryonic loss, moderate to marked edema of the endometrial folds in 12 of 12 treated mares and free fluid in the uterine lumen of 5 of 12 treated mares were detected by ultrasonography. After embryonic loss, Candida parapsilosis was cultured from the uteri of 8 of 12 treated mares, and E . coli was cultured from the uteri of 2 of 4 control mares. Postloss endometrial smears had cytologic evidence of inflammation in 10 of 12 treated mares and 3 of 4 control mares. Intrauterine inoculation of C. parapsilosis consistently induced embryonic loss and may provide a basis to further study the relationship between endometritis and embryonic loss in mares.

A new antibiotic combination for frozen bovine semen 1. Control of mycoplasmas, ureaplasmas, Campylobacter fetus subsp. venerealis and Haemophilus somnus.

Systematic evaluations of new combinations of antibiotics for the control of bovine mycoplasmas, ureaplasmas, Campylobacter fetus subsp. venerealis and Haemophilus somnus in a bovine frozen semen process were made. These organisms were standardized to 10(5) to 10(6) colony forming unit (CFU) and inoculated into each ml of raw semen. Antibiotics in a final volume of 0.02 ml were added to each ml of the raw semen and were contained at the same concentration in the nonglycerol portion of the extenders (whole milk, 20% egg yolk citrate, 20% egg yolk tris, Plus-X, and 28% egg yolk tris). The combination of gentamicin (500 ug/ml) tylosin (100 ug/ml) and Linco-Spectin (300/600 ug/ml) was more effective for the control of mycoplasmas and ureaplasmas and equally effective for the control of C. fetus subsp. venerealis and Haemophilus somnus than the standard combination of penicillin, dihydrostreptomycin and polymyxin B sulfate.

Isolation of Actinobacillus lignieresii from enlarged tongue of a horse.

In the horse described herein, Actinobacillus lignieresii was associated with a syndrome identical to wooden tongue in cattle. It responded rapidly to systemic sodium iodide and antibiotic therapy. The definitive diagnosis was based on cytologic examination and culture. If actinobacillosis is suspected, immediate treatment with sodium iodide should be instituted along with supportive therapy.