[show abstract][hide abstract] ABSTRACT: Nine horses from ages 5 to 21 years were diagnosed with cutaneous equine sarcoidosis (ES) over an 18-year period. In addition to skin, the lungs were frequently involved, with other organ systems affected less commonly. A predisposition for thoroughbreds and geldings was noted. Cutaneous lesions and signs included crusts, scales, alopecia and pruritus. These were found at various sites, particularly the legs/thighs/elbows, thorax, neck, face and ventral abdomen. Three horses were euthanized shortly after hospitalization; others survived as long as 12 years. Histopathologic stains, immunohistochemistry and polymerase chain reaction assays on paraffin-embedded cutaneous specimens from eight horses for Mycobacterium spp., Coccidioides immitis, Cryptococcus neoformans, Corynebacterium pseudotuberculosis, and Borrelia burgdorferi were all negative. The aetiology of ES is unlikely microbial and continues to be a diagnosis of exclusion. ES, when limited to the skin, is associated with a good prognosis, with either partial or complete response to glucocorticoid therapy in all the surviving horses.
[show abstract][hide abstract] ABSTRACT: To determine pharmacokinetics of azathioprine (AZA) and clinical, hematologic, and serologic effects of i.v. and oral administration of AZA in horses.
In study phase 1, a single dose of AZA was administered i.v. (1.5 mg/kg) or orally (3.0 mg/kg) to 6 horses, with at least 1 week between treatments. Blood samples were collected for AZA and 6-mercaptopurine (6-MP) analysis 1 hour before and at predetermined time points up to 4 hours after AZA administration. In study phase 2, AZA was administered orally (3 mg/kg) every 24 hours for 30 days and then every 48 hours for 30 days. Throughout study phase 2, blood samples were collected for CBC determination and serum biochemical analysis.
Plasma concentrations of AZA and its metabolite, 6-MP decreased rapidly from plasma following i.v. administration of AZA, consistent with the short mean elimination half-life of 1.8 minutes. Oral bioavailability of AZA was low, ranging from 1% to 7%. No horses had abnormalities on CBC determination or serum biochemical analysis, other than 1 horse that was lymphopenic on day 5 and 26 of daily treatment. This horse developed facial alopecia from which 1 colony of a Trichophyton sp was cultured; alopecia resolved within 1 month after the study ended.
Overall, no adverse effects were observed with long-term oral administration of AZA to horses, although 1 horse did have possible evidence of immunosuppression with chronic treatment. Further investigation of the clinical efficacy of AZA in the treatment of autoimmune diseases in horses is warranted.
American Journal of Veterinary Research 10/2005; 66(9):1578-83. · 1.35 Impact Factor
[show abstract][hide abstract] ABSTRACT: To assess heritability and mode of inheritance for hereditary equine regional dermal asthenia (HERDA) in Quarter Horses.
1,295 horses with Quarter Horse bloodlines, including 58 horses affected with HERDA.
Horses were classified as affected or unaffected or as undetermined when data were insufficient to assess phenotype. Pedigree data were analyzed to determine the probable mode of inheritance. Heritability was estimated by use of Bayesian statistical methods.
Heritability (mean+/-SD) of HERDA was estimated to be 0.38+/-0.13, with both sexes having an equal probability of being affected. Results for evaluation of the pedigrees were consistent with a single Mendelian autosomal recessive mode of inheritance.
HERDA in Quarter Horses is an inherited disease, and affected horses are more likely to produce affected offspring. An autosomal recessive mode of inheritance should be considered by people making breeding decisions involving Quarter Horses when a first-degree relative has been confirmed with HERDA or has produced affected offspring. In addition, breeders whose horses have produced affected offspring can reduce the likelihood of producing affected horses in the future by avoiding inbreeding.
American Journal of Veterinary Research 04/2005; 66(3):437-42. · 1.35 Impact Factor
[show abstract][hide abstract] ABSTRACT: A 9-yr-old, female Bactrian camel (Camelus bactrianus) developed severe pruritus in June 1993. During the next 8 yr, the camel exhibited annual episodes of pruritus and epiphora, generally beginning in June and subsiding in October of each year. These signs could usually be controlled with topical agents and fly repellents, although pruritus flare-ups were effectively controlled with intermittent injections of diphenhydramine and corticosteroids. There were no signs during the colder months. The pruritus became more severe and difficult to control when the camel reached its 18th year. Histopathologic descriptions of skin biopsies taken from several sites suggested a hypersensitivity reaction with secondary changes because of bacterial infection or corticosteroid administration (or both). An intradermal test (IDT) performed using 62 allergens regionalized to Northern California resulted in 17 positive test sites. Hyposensitization therapy was initiated using allergens chosen on the basis of exposure, availability, and the results of the IDT, using standard protocols. The clinical signs of pruritus were markedly reduced in the 2 yr after the hyposensitization injections were initiated.
Journal of Zoo and Wildlife Medicine 04/2005; 36(1):88-94. · 0.43 Impact Factor
[show abstract][hide abstract] ABSTRACT: To evaluate a method of aerobic bacteriologic culture of epidermal collarette specimens from dogs with superficial pyoderma and compare results with those for aerobic bacteriologic culture of abdominal skin specimens in healthy dogs.
22 dogs with epidermal collarettes and 24 healthy dogs.
Dry sterile cotton swabs were rolled across epidermal collarettes or hairless areas of abdominal skin in healthy dogs and submitted for aerobic bacteriologic culture. Hemolytic colonies of gram-positive-staining cocci were tested for catalase production, and if results were positive, a coagulase test was performed. Colonies with coagulase activity were tested for the ability to ferment mannitol. Antimicrobial susceptibility testing was performed on all Staphylococcus spp that were isolated.
S. intermedius was isolated from collarettes in 18 of 22 dogs with superficial pyoderma but not from healthy dogs. Estimated sensitivity and specificity of the culture method were 81.8% and 100%, respectively. There were no significant differences in the ability to culture S. intermedius, the number of S. intermedius isolates without resistance to antimicrobials, and the number of S. intermedius isolates resistant to penicillin G when comparing dogs with superficial pyoderma for the first time and dogs with recurrent pyoderma, dogs that did or did not receive concurrent antimicrobials, and dogs with and without underlying allergic disease.
Bacteriologic culture of epidermal collarette specimens was a simple and reliable method for identification of S. intermedius in dogs with superficial pyoderma, regardless of history of pyoderma or current antimicrobial use.
Journal of the American Veterinary Medical Association 04/2005; 226(6):904-8. · 1.72 Impact Factor
[show abstract][hide abstract] ABSTRACT: Twenty horses with pemphigus foliaceus were seen over a period of 15 years in a veterinary medical teaching hospital. Breeds seen were seven quarterhorses, five thoroughbreds, three cross-bred horses, two Arabians and one of each of the following: standardbred, Tennessee walker and warmblood. There was no breed, age or sex predisposition. Nine were mares, ten were geldings and one was a stallion. Ages ranged from 2.5 months to 25 years, with a mean of 8.6 years. Sixteen (80%) of the pemphigus foliaceus horses first exhibited signs between September and February. There was a statistically significant more common occurrence of pemphigus foliaceus during those months. Signs in the four other horses were first noted in March, May or June. Three of those horses were < 13 months of age. Oedema (14/20) and crusts (13/20) were the most common lesions. Pain was present in 9/20 horses, pruritus in 7/20 and pyrexia in 7/20. Follow-up was available for 13 horses. Five of these horses were euthanased. In three horses the reason for euthanasia was laminitis secondary to treatment. Four horses remained lesion-free after medication was discontinued. Two horses required maintenance medication and are doing well at the time of writing.
[show abstract][hide abstract] ABSTRACT: Data on fifty horses with hereditary equine regional dermal asthenia (HERDA; "hyperelastosis cutis") were collected on clinical, histopathological, ultrastructural and immunohistological findings. All horses were Quarter horses or of Quarter horse ancestry. Pedigree evaluation strongly supported an autosomal recessive mode of inheritance. The most common lesions were seromas/haematomas, open wounds, sloughing skin, and loose, easily tented skin that did not return to its initial position. Definitive diagnosis could not be made via histopathology, although the presence of tightly grouped thin and shortened collagen fibres arranged in clusters in the deep dermis was suggestive of the disease. Trichrome, acid orcein-Giemsa and immunohistochemical stains for collagens I and III showed no consistent abnormalities compared to control horses; an increase in elastic fibres was not a consistent finding. Electron microscopy showed no abnormalities in the periodicity of the collagen bundles; neither orientation nor variation of cross-section diameter of the collagen fibrils differentiated control from affected horses. The diagnosis of HERDA relies on clinical presentation, but may be supported by suggestive (although not pathognomonic) histopathological lesions.
[show abstract][hide abstract] ABSTRACT: A skin lesion classified as a vascular malformation is reported in a young-adult, female guinea pig. The physical examination revealed a 3 x 2-cm irregularly shaped violaceous plaque located on the left caudal flank. The surface of the plaque was ulcerated and bled intermittently, resulting in fatal blood loss. On histology the mass consisted of variably sized vascular spaces filled with red blood cells and variable amounts of extramedullary haematopoietic cells, lined by well-differentiated endothelial cells often surrounded by one layer of spindle-shaped cells. Based on immunohistochemistry, the spindle cell population was confirmed to be smooth muscle cells and no proliferation of endothelial cells was found with the Ki67 proliferation marker. Histological and immunohistochemical findings were consistent with a vascular malformation. Classification of vascular malformations and potential treatments are discussed. To the authors' knowledge, this is the first reported case of a cutaneous vascular lesion in a guinea pig.
[show abstract][hide abstract] ABSTRACT: Clinical and diagnostic parameters, and response to topical mupirocin in 25 cats with feline acne are described. The chin was the most common area affected, but the lower lip, upper lip and the commissure of the lips also frequently had lesions. The most common clinical sign was the presence of crusts, followed by comedones, erythema, alopecia, pruritus and nodules/fistulas. Deep skin scrapings for ectoparasites, cytological examination of superficial skin scrapings, and fungal cultures from the chin were performed on all cats. Dermatophytes were cultured from two cats and Malassezia pachydermatis was cultured (n = 2), seen on cytology smears (n = 1), or noted on histopathology (n = 1). Skin biopsies were obtained from three of the cats and most commonly showed dilatation of sebaceous gland ducts, neutrophilic or pyogranulomatous infiltration of the sebaceous glands, and pyogranulomatous inflammation of the dermis.All cats were treated with topical 2% mupirocin ointment twice daily for 3 weeks as the sole treatment. Treatment response was excellent in 15 cats and good in nine cats. One cat had a contact reaction to the mupirocin, necessitating stopping treatment. The response to treatment of the six cats with dermatophyte or years involvement was good (n = 3) or excellent (n = 3).
[show abstract][hide abstract] ABSTRACT: Four dogs developed cutaneous lesions following the administration of various antibiotics. Histopathology of the lesions was compatible with pemphigus foliaceus, although apoptotic cells suggestive of erythema multiforme were seen in two cases. In two dogs the lesions resolved after 7.5-8.5 months of immune-suppressive treatment. No recurrence was seen during the follow-up period (3 and 4.5 years). The lesions in the other two dogs resolved within 3 weeks to 3 months following discontinuation of the antibiotic. No recurrence of clinical signs occurred during the follow-up period (1 and 4 years, respectively).
[show abstract][hide abstract] ABSTRACT: The medical records of 266 dogs diagnosed as having atopic dermatitis were reviewed. Statistical data were evaluated referable to breed predilections, clinical signs and positive reactions to allergens. Positive reactions were most common to house dust mites (more common with clinical signs in the fall) followed by moulds (more common with clinical signs in the fall and spring). Dogs with positive reactions to moulds, trees or cultivated plants were more likely to have skin and ear yeast infections. Dogs with positive reactions to cultivated plants were more likely to have otitis externa and pedal lesions. Positive reactions to house dust were more common in dogs with early onset of signs and in those tested early in the disease. Dogs had more positive reactions to weeds when allergy tests were performed in the summer and fall. Positive reactions to flea antigen were highly correlated with the clinical diagnosis of flea allergy dermatitis.
[show abstract][hide abstract] ABSTRACT: One hundred and sixty-nine dogs were diagnosed with atopic dermatitis, and treated with hyposensitization for at least 1 year based on the results of either intradermal skin tests (IDST) or enzyme-linked immunosorbant serum assays (ELISA). Excellent (i.e. hyposensitization alone controlled clinical signs), good (> 50% improvement), moderate (< 50% improvement) and no (clinical signs were unchanged) responses were seen in 19.5, 32.5, 20.1 and 27.8%, respectively. Age of onset, age when treatment was initiated or the duration of clinical signs had no influence on response to hyposensitization. Dogs having concurrent flea allergy dermatitis were statistically more likely to respond better than dogs with concurrent food allergies. Although not statistically significant, there were trends for Golden Retriever and male dogs to respond better than other breeds and female dogs, respectively. Dogs having more than 21 positive reactions in allergy tests and treated with more than 21 allergens had lower response scores, and a longer time course before achieving beneficial response. Lower response scores were seen in dogs having positive reactions to cultivated plants, grasses, trees or insects. There was no difference in response to hyposensitization whether based on IDST or ELISA results.
[show abstract][hide abstract] ABSTRACT: Antihistamines were prescribed for 178 of 271 dogs with a diagnosis of atopic dermatitis at the Veterinary Medical Teaching Hospital of the University of California, Davis from 1992 to 1998. Fifty-four percent of 166 dogs given antihistamines responded favorably to these treatments, with 27% of the responses rated as good and 27% rated as moderate. Diphenhydramine and hydroxyzine were the most commonly used antihistamines and were the most frequently effective. Chlorpheniramine and clemastine were administered less frequently and had much lower positive response rates. Responses to antihistamines as a group were significantly better in dogs having onset of clinical signs at younger ages (odds ratios for 1-year increase in age = 0.72, 95% confidence interval = 0.57 to 0.91, P =.005).
Veterinary therapeutics: research in applied veterinary medicine 02/2002; 3(1):88-96. · 1.69 Impact Factor
[show abstract][hide abstract] ABSTRACT: A third-generation fluoroquinolone, pradofloxacin (PRA), is currently being developed to treat bacterial infections in dogs. The purpose of this study was to assess the clinical efficacy in 20 dogs affected with superficial and deep pyoderma. An initial aerobic skin culture was performed in dogs with superficial pyoderma; aerobic/anaerobic tissue culture was performed in dogs with deep pyoderma; and skin cytology and biopsies were obtained from all dogs. Pradofloxacin (approximately 3 mg/kg per os [PO]) was administered daily to all dogs. Clinical efficacy was recorded at 4 weeks for dogs with superficial pyoderma and at 3 and 6 weeks for dogs with deep pyoderma. At a mean dosage of 3.7 mg/kg PO once daily, PRA treatment resulted in an excellent to good clinical response within 3 to 6 weeks for all 20 dogs with superficial and deep pyoderma.
Journal of the American Animal Hospital Association 46(5):301-11. · 0.76 Impact Factor
[show abstract][hide abstract] ABSTRACT: Acral lick dermatitis ("lick granuloma") in dogs is often thought to have a behavioral etiology. However, other diseases may cause lesions on the distal legs, mimicking acral lick dermatitis. In this report, six dogs were presented with acral lick dermatitis-like lesions from different underlying causes-namely lymphoma, an orthopedic pin, deep pyoderma, mast cell tumor, leishmaniasis, and (presumptive) sporotrichosis.
Journal of the American Animal Hospital Association 43(4):215-20. · 0.76 Impact Factor