Results suggest that antimicrobial agents chosen for the initial treatment of dogs and cats with pyothorax should be active against a mixture of obligate anaerobic and facultative bacteria.

Abstract.Intestinal colonization with toxigenic strains of Clostridium difficile was documented in 9 of 10 horses with acute onset diarrhea in a veterinary medical teaching hospital, whereas a similar isolate was detected in only 1 of 23 other horses without diarrhea in the hospital. One horse with diarrhea was infected simultaneously with both C. difficile and Salmonella krefeld. Clostridium difficile was detected by fecal culture on selective medium, confirmed with a latex particle agglutination test, and identified as toxigenic by polymerase chain reaction amplification of toxin A and toxin B gene sequences. Using an arbitrarily-primed polymerase chain reaction, 6 distinct C. difficile isolates were detected in the feces of the 9 affected horses at the time of the outbreak of diarrhea.Although species of the genus Clostridium, particMaterials and methods ularly C. perfringens, are known causes for enterocolitis in neonatal foals, the role of C. difficile as an enteroAnimals. In the spring of 1993, 10 adult horses developed pathogen in the adult horse is largely unknown. Intesdiarrhea in a 2-day period in the large animal clinic of the tinal colonization with C. difficile has been described University of California Veterinary Medical Teaching Hospital. The affected horses had been hospitalized for periods in the horse, 12 and there are reports of C. difficile in-of time ranging from 0 to 22 days, and 7 of the 10 horses fection in neonatal foals with associated necrotizing enterocolitis 7-9 and in an adult horse with typhlocolitis. 15 Despite the relative paucity of information regarding intestinal colonization of horses with C. difficile, the organism is a common nosocomial pathogen in human patients and causes pseudomembranous colitis associated with antibiotic therapy. 10,18 Several studies have confirmed the presence of C. difficile in animals in veterinary practices and teaching hospitals, although those reports were limited to examinations of small animals. 2,3,13,22 We recently dehad been in the hospital for 4 days or longer. All of the horses were receiving 1 or more antibiotics (ampicillin, 6 horses; gentamicin, 8 horses; ceftiofur, 1 horse; trimethoprim-sulfamethoxazole, 1 horse), and all but 2 of the horses were hospitalized for colic or diarrhea. Four of these horses had had celiotomies during their treatment for colic. Of the two horses without colic, one had uterine torsion and another was undergoing treatment for a subepiglottic mass. Affected horses were located in 4 separated areas (different buildings) of the hospital at the time of fecal sampling. There were 23 other horses without diarrhea in the hospital at this time.Laboratory methods. Specimens of the diarrheal feces were tected C. difficile in small animal patients in our teaching hospital, and although both toxigenic and nontoxigenic isolates were detected, the association between intestinal colonization and clinical signs was not clear. 20In the present study, we present evidence of colonization of adult horses with toxigenic strains...

Positive cultures were obtained from 60 equine orthopedic cases during a 12 year period (1974-1985). These cases consisted of 34 long or cuboidal bone fractures, 13 arthrotomy/arthroscopy procedures for removal or internal fixation of a fracture, 7 proximal splint bone fractures, and 6 facial or mandibular fractures. Excluding the 13 arthrotomies, only 10 (21%) of the 47 were open fractures. Multiple organisms were isolated from 36 cases (20 long or cuboidal bone fractures, 7 splint bone fractures, 5 mandibular fractures, and 4 intra-articular fractures). Of the 142 isolates, 35 (24%) were members of the family Enterobacteriaceae, 33 (23%) Streptococcus spp., and 25 (18%) Staphylococcus spp. with the majority being coagulase positive (65%). Other organisms isolated were Pseudomonas spp. (16, 11%), obligate anaerobes (11, 7%), and Actinobacillus spp. (7, 5%). the remaining 10% consisted of Pasteurella spp., Bacillus spp., Corynebacterium spp., Micrococcus spp., and Actinomyces spp. When comparing results between two time periods (1974-1979 and 1980-1985) there was an increase in the percentage of coagulase positive staphylococci isolates resistant to all antimicrobics tested except oxacillin and amikacin, and Escherichia coli isolates were resistant to all but amikacin. For Pseudomonas spp., resistance to gentamicin increased in the second time period (1980-1986). During the initial time period (1974-1979) culture tests for obligate anerobes were not conducted until 1975. No anerobes were cultured during those initial 5 years; however, one third of those isolated after 1980 were resistant to penicillin and ampicillin.(ABSTRACT TRUNCATED AT 250 WORDS)

A total of 268 isolates of coagulase-positive staphylococci from a variety of animal species, including dogs, horses, cats, monkeys, goats, and cows, were assigned to species on the basis of the API Staph-Ident system (Analytab Products, Inc., Plainview, N.Y.). Of 195 isolates from dogs, 179 (91.8%) were Staphylococcus intermedius, as were 9 of 25 (36%) isolates from horses, 7 of 15 (46.6%) isolates from cats, and 4 of 6 (66.6%) isolates from goats. Only 1 of 10 isolates from monkeys and none of 7 isolates from cows were S. intermedius. Of the remaining 68 cultures, 63 were identified as Staphylococcus aureus and 5 as Staphylococcus hyicus. The latter identifications were rendered doubtful on the basis-of conventional tests. Identification appeared to be more certain in the S. aureus sample than in the S. intermedius sample. Distribution of biotypes within the two bacterial species as represented by different API profile numbers and reactivity on test substrates showed no significant variations among the host species, except for the S. aureus biotypes in dogs. Both Staphylococcus species were represented about equally among samples from different tissues and lesions, apart from skin-related infections in dogs, which were associated exclusively with S. intermedius (P < 0.01). Differences between S. aureus and S. intermedius in antimicrobial susceptibility patterns, prevalence of clumping factor, and occurrence of beta-toxin were found to be not significant.