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Abstract.A 6-month-old, castrated male domestic cat with progressive neurological signs of 2-3 weeks duration was necropsied. Macroscopic findings were restricted to the brain and included irregularly shaped, well-delineated but unencapsulated areas of intense black pigmentation involving the rostral portion of both cerebral hemispheres. Microscopically, numerous brown, oblong, segmented branching hyphae and conidiallike structures and extensive pyogranulomatous inflammation were identified throughout the cerebral lesion and in adjacent blood vessels. Hyphae and oval conidia were best demonstrated with either Gomori methenamine silver or periodic acid-Schiff stain. Fungal infection in the brain of this cat was unrelated to any concurrent immunodeficiency syndrome or immunosuppressive treatment. This report deals with a case of cerebral phaeohyphomycosis from which a different species of dematiaceous fungus, Cladophialophora bantiana, was isolated and identified.

A single cefovecin injection (8 mg/kg) administered SC, which could be repeated once after 14 days, was safe and effective against naturally occurring skin infections in dogs and as effective as cefadroxil administered PO twice daily for 14 or 28 days.

Enterococcus (Streptococcus) durans is a motile, Grampositive coccus found in the alimentary tract of animals and in water, soil, sewage, and vegetati~n.~.~ Enteric disease and diarrhea were first associated with E. durans when Grampositive cocci were seen adhered to enterocytes in the small intestine of diarrheic pigs' and foals.Io E. durans subsequently was shown to induce diarrhea in gnotobiotic pigs7Jo and conventionally reared foalsI0 challenged with strains of porcine or equine origin.Diarrhea of 8 hours duration occurred in eight of ten, 1 1 -day-old Plott hound pups from a private residence. The bitch had been vaccinated against distemper, hepatitis, and parvovirus and did not have clinical signs. Despite intensive fluid and antimicrobial therapy, three pups died, and one of these was presented dead for necropsy. At necropsy, the pup was in excellent flesh, moderately dehydrated, and had severe hyperemia of the small intestinal wall from the duodenum through the jejunum. Scant amounts of liquid brown feces were present in the large intestine.Kidney and jejunum were fixed in 10% neutral-buffered formalin, embedded in paraffin, sectioned, and examined after staining with hematoxylin and eosin and Gram's stains. Pieces (0.5 cmz) of formalin-fixed small intestine were immersed in 3% glutaraldehyde in 0.1 M sodium phosphate buffer at pH 7.2 and refrigerated at 4 C until processed for transmission and scanning electron microscopic examinations by procedures described previ~usly.~ Portions of small intestine were inoculated onto sheep blood, brilliant green, MacConkey and cholistin naladixic acid agars, and incubated aerobically at 37 C. Feces were processed and negatively stained using procedures described previously8 and examined using an electron microscope.Microscopically, villi in the jejunum were long, slender, and densely colonized by Gram-positive coccoid bacteria (Figs. 1, 2). Bacterial colonization of enterocytes extended from the tips to the base of villi. The morphologic structure of enterocytes in areas with bacterial adherence was unaltered, except for changes attributed to post-mortem decomposition. Intestinal crypts were orderly in arrangement and structure, although a few crypts were dilated and contained neutrophils. Blood vessels in the submucosa, tunica muscularis, and serosa were dilated and blood-filled. The lumens of venules in the lamina propria were sometimes occluded by fibrinous thrombi. A few neutrophils were admixed with coccoid and rod bacteria in the jejunal lumen; but in general, inflammation was mild.Ultrastructurally, coccoid bacteria were closely apposed to enterocytes (Fig. 3). Fine filaments consistent in morphologic structure with fimbriae extended from bacterial cell walls to adjacent bacteria and to enterocyte brush borders (Fig. 3). Swelling of cytoplasmic organelles and distortion of microvilli most likely resulted from post-mortem decomposition. Intracellular cocci were frequently seen within lysozomes of villous epithelial cells; but the morphologic integrity of intra...

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Sporotrichosis was diagnosed in a 2-year-old male Golden Retriever that was allowed to roam free on the owner's Christmas tree farm in Minnesota. Clinical signs had been evident for 1 month and included swelling of the claw bed of the third digit on the left forelimb and a fluctuant nodular lesion in the area of the left carpus. Few organisms were seen in affected tissues, and diagnosis was confirmed on the basis of results of fungal culture. The condition responded to treatment with itraconazole. Previous reports of sporotrichosis in dogs have described lesions that were distributed predominantly on the head, ears, and trunk. A history of exposure to environments that favor survival of the organism may be an important consideration when evaluating animals suspected to have sporotrichosis. To the authors' knowledge, use of itraconazole to treat a dog with sporotrichosis has not been reported previously.

The Clinical and Laboratory Standards Institute (CLSI) uses cephalothin as the class representative for testing veterinary isolates for susceptibility to other first-generation cephalosporins, including cephalexin. We examined replacing cephalothin with cephalexin because cephalexin is used more often clinically. Bacterial isolates were obtained from dogs and cats from a national surveillance program. CLSI testing methods were used to determine the MIC for 4 cephalosporins used in veterinary medicine. Cephalexin clinical breakpoints for canine isolates were established by using published pharmacokinetic data and Monte Carlo simulations to calculate the probability of target attainment (PTA). For 1,112 Staphylococcus pseudintermedius isolates, the mode, MIC, and MIC were 1, 2, and 64 µg/mL, respectively, for cephalexin, and ≤0.06, 0.12, and 2 µg/mL for cephalothin. Susceptibility of S. pseudintermedius from 2011 to 2014 did not change for the 4 cephalosporins tested. Only 4.3% of the penicillin-binding protein 2a-positive S. pseudintermedius isolates had MIC values ≤2 µg/mL for cephalexin, but 66.3% of these isolates had MIC values ≤2 µg/mL for cephalothin. There were also discrepancies between cephalexin and cephalothin for other bacteria tested, but the largest difference was for S. pseudintermedius, with a MIC difference of 4 doubling dilutions. Cephalexin interpretive categories (breakpoints) of ≤2 μg/mL (susceptible), 4 μg/mL (intermediate), and ≥8 μg/mL (resistant) were established for isolates obtained from dogs. Cephalothin should not be used for susceptibility testing of cephalexin for veterinary bacterial pathogens, and canine-specific breakpoints should be used for testing susceptibility. Breakpoints determined using the methods described herein for the interpretive categories will be added to future CLSI tables to reflect this recommendation.

1 SC injection of 8 mg of cefovecin/kg for the treatment of cats with naturally occurring skin infections (wounds and abscesses) was safe and as effective as cefadroxil administered orally at 22 mg/kg, once daily for 14 days.