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in Journal of the American Veterinary Medical Association

Abstract

Case Description—A closed herd of 400 mixed-breed dairy goats was examined because of a decrease in milk production and increase in mortality rate. Nine animals had died within a 1-month period.

Clinical Findings—Clinical signs were evident only in lactating goats and included anorexia and recumbency. In the most severely affected goats, signs progressed to neurologic abnormalities and death. Serum aspartate aminotransferase activity, γ-glutamyltransferase activity, and total bilirubin concentration were high in clinically affected does, but no evidence of hemolysis was found. A diagnosis of copper toxicosis was made on the basis of high liver and kidney copper concentrations and histologic evidence of hepatic necrosis. Goats were found to have been fed a mineral mix containing 3,050 ppm copper for 9 months prior to the onset of copper toxicosis. Overall, there was no consistent relationship between serum hepatic enzyme activities, serum copper concentration, and liver copper concentration.

Treatment and Outcome—Clinically affected goats were treated with penicillamine, ammonium molybdate, sodium thiosulfate, and vitamin E. Penicillamine increased urine copper excretion in treated does versus untreated control animals. An increased incidence of infectious disease was identified in the herd 9 months later. Liver vitamin E concentration was low in 10 of the 12 goats that underwent necropsy.

Clinical Relevance—Findings suggested that penicillamine may be an effective treatment for goats with copper toxicosis. Production losses months after the diagnosis was made suggested that the intoxication had a prolonged animal welfare and economic impacts.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine penetration of topically and orally administered voriconazole into ocular tissues and evaluate concentrations of the drug in blood and signs of toxicosis after topical application in horses.

Animals—11 healthy adult horses.

Procedure—Each eye in 6 horses was treated with a single concentration (0.5%, 1.0%, or 3.0%) of a topically administered voriconazole solution every 4 hours for 7 doses. Anterior chamber paracentesis was performed and plasma samples were collected after application of the final dose. Voriconazole concentrations in aqueous humor (AH) and plasma were measured via high-performance liquid chromatography. Five horses received a single orally administered dose of voriconazole (4 mg/kg); anterior chamber paracentesis was performed, and voriconazole concentrations in AH were measured.

Results—Mean ± SD voriconazole concentrations in AH after topical administration of 0.5%, 1.0%, and 3.0% solutions (n = 4 eyes for each concentration) were 1.43 ± 0.37 μg/mL, 2.35 ± 0.78 μg/mL, and 2.40 ± 0.29 μg/mL, respectively. The 1.0% and 3.0% solutions resulted in significantly higher AH concentrations than the 0.5% solution, and only the 3.0% solution induced signs of ocular toxicosis. Voriconazole was detected in the plasma for 1 hour after the final topically administered dose of all solutions. Mean ± SD voriconazole concentration in AH after a single orally administered dose was 0.86 ± 0.22 μg/mL.

Conclusions and Clinical Relevance—Results indicated that voriconazole effectively penetrated the cornea in clinically normal eyes and reached detectable concentrations in the AH after topical administration. The drug also penetrated noninflamed equine eyes after oral administration. Low plasma concentrations of voriconazole were detected after topical administration.

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

To evaluate the effectiveness of canine parvovirus monoclonal antibody (CPMA) as a treatment against canine parvovirus (CPV-2)–induced mortality and to support USDA product licensure.

ANIMALS

28 purpose-bred Beagle dogs aged 8 weeks were randomized to the treated (n = 21) or control (7) group.

METHODS

Dogs were challenged intranasally with 104.2 TCID50 virulent CPV-2b on Day 0 and monitored for 14 days for fecal viral shed and clinical disease. All dogs began shedding CPV-2 on Day 4 and were treated intravenously with a single dose of either CPMA (0.2 mL/kg) or saline (equal volume). No additional treatments were given to either group. Feces and sera were collected for quantitative analysis of fecal viral shed (hemagglutination) and antibody responses (hemagglutination inhibition and dot-blot ELISA), respectively. Dogs were monitored twice daily for parameters including lymphopenia, fever, vomiting, abnormal feces, inappetence, and lethargy. Humane endpoints triggered euthanasia by a veterinarian masked to treatment groups. The primary outcome variable was prevention of mortality as compared to controls.

RESULTS

Mortality was prevented in all CPMA-treated dogs compared to 57% mortality in the control group (P = .0017, Fisher exact test). Canine parvovirus monoclonal antibody–treated dogs also experienced less severe and/or shorter durations of diarrhea, fever, vomiting, CPV-2 shedding in feces, and lymphopenia. Both groups showed similar immunoglobulin M responses as measured by semiquantitative analysis.

CLINICAL RELEVANCE

Intravenous administration of CPMA can effectively improve clinical outcome when administered early in CPV-2 disease. Canine parvovirus monoclonal antibody treatment after proven infection does not interfere with adaptive immunity.

Open access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate the effects of interleukin (IL)-1β on proteoglycan metabolism in equine cartilage explants when cultured in the presence of synoviocytes.

Sample Population—Samples of cartilage and synovium collected from the femoropatellar joints of three 2- to 3-year-old horses.

Procedures—3 experimental groups were established: cartilage explants only, synoviocytes only, and cartilage explants-synoviocytes in coculture. In each group, samples were cultured with or without IL-1β (10 ng/mL) for 96 hours. Glycosaminoglycan (GAG) content of cartilage and medium samples was measured by use of a spectrophotometric assay; RNA was isolated from synoviocytes and cartilage and analyzed for expression of matrix metalloproteinases (MMP)-3 and -13 (cartilage and synoviocytes), aggrecan (cartilage), collagen type IIB (cartilage), and 18S as a control (cartilage and synoviocytes) by use of quantitative PCR assays. Cartilage matrix metachromasia was assessed histochemically.

Results—IL-1β–induced GAG loss from cartilage was significantly less in cocultures than in cartilage-only cultures. Cartilage aggrecan gene expression was also significantly less downregulated and synoviocyte MMP-3 expression was less upregulated by IL-1β in cocultures, compared with cartilage- and synoviocyteonly cultures. Histochemical findings supported the molecular and biochemical results and revealed maintenance of matrix metachromasia in cocultured cartilage treated with IL-1β.

Conclusions and Clinical Relevance—Results suggest that synoviocytes secrete 1 or more mediators that preferentially protect matrix GAG metabolism from the degradative effects of IL-1β. Further studies involving proteomic and microarray approaches in similar coculture systems may elucidate novel therapeutic targets for the treatment of osteoarthritis.

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE To evaluate the knowledge of various veterinary specialists regarding various radiation safety matters and determine the availability of radiation safety training.

DESIGN Cross-sectional study.

SAMPLE 164 radiology, 81 internal medicine, and 108 emergency and critical care (ECC) specialists.

PROCEDURES An online survey was developed regarding knowledge of and training in radiation safety, and invitations were sent via email through the email lists of the veterinary internal medicine, ECC, and radiology specialty colleges. Responses were summarized, and comparisons were made between radiologists and internal medicine and ECC clinicians.

RESULTS 65.5% (38 /58) of respondents from academic institutions and 30.0% (33/110) of respondents from private practices indicated that radiation safety training was mandatory at their institution for personnel who work with ionizing radiation–emitting equipment, and 80.2% (85/106) and 56.6% (77/136), respectively, had received some radiation safety training. Low proportions of radiologists and internal medicine and ECC clinicians correctly identified the effective dose of ionizing radiation associated with 3-phase esophagography and 3-phase abdominal CT. Many radiologists (92/153 [60.1%]) and nonradiologists (92/179 [51.4%]) believed that the effective doses used in veterinary practice pose no increased risk of fatal cancer to their patients.

CONCLUSIONS AND CLINICAL RELEVANCE Radiation safety training, although more common in academia, was not universally available and may not meet radiography equipment license requirements for some institutions. Most radiologists, internal medicine clinicians, and ECC clinicians had a poor understanding of the amount of ionizing radiation associated with medical imaging procedures and the potential hazards to their patients.

Full access
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE

This study aimed to characterize the bacterial and eukaryotic microbiota of the gastrointestinal (GI) tract in domestic rabbits and to evaluate the effect of different diet characteristics, such as pelleting, extrusion, and hay supplementation.

ANIMALS

30 New Zealand White rabbits (15 male and 15 female; 6 to 7 months old) were fed 1 of 6 diets (5 rabbits per diet) for 30 days after an initial acclimation period. At the end of the trial, samples were collected from the stomach, small intestine, cecum, large intestine, and hard feces.

METHODS

The samples were analyzed using 16S rRNA and internal transcribed spacer 1 region-targeted amplicon sequencing.

RESULTS

The bacterial microbiota was distinct between the foregut and hindgut. The most abundant bacterial genera included an unclassified genus in the Bacteroidales order and Alistipes. Candida was the most abundant genus in the eukaryotic dataset. In the bacterial dataset, diet No Hay/Pellet E was shown to have lower diversity (Shannon diversity, P < .05) compared to all diet groups except for No Hay/Pellet M. Few significant differences in alpha-diversity indexes between diet groups were detected in the eukaryotic dataset.

CLINICAL RELEVANCE

Our findings demonstrated that feeding hay had a significant effect on the beta diversity of the bacterial microbiota. Given the prevalence of gastrointestinal disease in the domestic rabbit population, furthering our understanding of what constitutes a healthy rabbit microbiota and the effects of different diets on the microbial community can help veterinarians implement better intervention strategies and allow pet owners to provide the best level of care.

Open access
in American Journal of Veterinary Research

Objective

To determine effects of blood contamination on western blot (WB) analysis of CSF samples for detection of anti-Sarcocystis neurona antibodies, and on CSF albumin and IgG concentrations, albumin quotient (AQ), and IgG index in horses.

Design

Prospective in vitro study.

Samples

Blood with various degrees of immunoreactivity against S neurona was collected from 12 healthy horses. Cerebrospinal fluid without immunoreactivity against S neurona was harvested from 4 recently euthanatized horses.

Procedure

Blood was serially diluted with pooled nonimmunoreactive CSF so that final dilutions corresponded to 10-3 to 100 μl of blood/ml CSF, and WB analysis was performed on contaminated CSF samples. Number of RBC, albumin and IgG concentrations, AQ, and IgG index were also determined.

Results

Antibodies against S neurona were detected in CSF contaminated with 10-3 μl of strongly immunoreactive blood/ml. In CSF samples contaminated with 10 μl of blood/ml, AQ remained within reference range. Volume of blood required to increase IgG index varied among blood samples and was primarily influenced by serum IgG concentrations. Number of RBC in contaminated samples was correlated with volume of blood added, but not with degree of immunoreactivity detected in contaminated CSF samples.

Conclusions and Clinical Relevance

During collection of CSF from horses, contamination with blood may introduce serum antibodies against S neurona at concentrations sufficient for detection by WB analysis, thus yielding false-positive results. When blood is moderately or strongly immunoreactive, the amount of contaminating albumin may be small enough as to not increase AQ above reference range. In these cases, AQ and IgG index should be interpreted with caution. (J Am Vet Med Assoc 1999;215:67—71)

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the prevalence of antibodies against 6 Leptospira serovars and determine risk factors associated with positive Leptospira titers in healthy client-owned dogs in Michigan.

Design—Cross-sectional study.

Animals—1,241 healthy dogs at least 4 months of age.

Procedures—Dogs were examined by veterinarians at private practices. Vaccinated and unvaccinated dogs were enrolled in the study, which occurred prior to the availability of a 4-serovar (Canicola, Grippotyphosa, Icterohaemorrhagiae, and Pomona) Leptospira vaccine. Sera were tested by use of the microscopic agglutination test to determine antibody titers against Leptospira serovars Bratislava, Canicola, Grippotyphosa, Hardjo, Icterohaemorrhagiae, and Pomona. A questionnaire was used to collect demographic information about each dog to identify risk factors associated with seropositive status.

Results—309 of 1,241 (24.9%) dogs had antibody titers against at least 1 of the 6 Leptospira serovars, which suggested exposure to Leptospira spp. Prevalence of antibodies was highest to serovar Grippotyphosa, followed by Bratislava, Canicola, Icterohaemorrhagiae, and Pomona. Age, travel outside Michigan, exercise outside fenced yards, and exposure to livestock and wildlife were significant risk factors for positive titers.

Conclusions and Clinical Relevance—Among healthy dogs from the lower peninsula of Michigan, > 20% have antibodies against leptospiral serovars historically considered uncommon but more recently incriminated as causing clinical canine leptospirosis. Wildlife and livestock may be of increasing importance as reservoirs for canine leptospirosis as urbanization continues to occur. Expanded vaccination strategies may partially mitigate these trends.

Full access
in Journal of the American Veterinary Medical Association