Search Results

Abstract

Objective—To determine current practices regarding use of antimicrobials in equine patients undergoing surgery because of colic at veterinary teaching hospitals.

Design—Survey.

Sample Population—Diplomates of the American College of Veterinary Surgeons performing equine surgery at veterinary teaching hospitals in the United States.

Procedure—A Web-based questionnaire was developed, and 85 surgeons were asked to participate. The first part of the survey requested demographic information and information about total number of colic surgeries performed at the hospital, number of colic surgeries performed by the respondent, and whether the hospital had written guidelines for antimicrobial drug use. The second part pertained to nosocomial infections. The third part provided several case scenarios and asked respondents whether they would use antimicrobial drugs in these instances.

Results—Thirty-four (40%) surgeons responded to the questionnaire. Respondents indicated that most equine patients undergoing surgery because of colic at veterinary teaching hospitals in the United States received antimicrobial drugs. Drugs that were used were similar for the various hospitals that were represented, and for the most part, the drugs that were used were fairly uniform irrespective of the type of colic, whereas the duration of treatment varied with the type of colic and the surgical findings. The combination of potassium penicillin and gentamicin was the most commonly used treatment.

Conclusions and Clinical Relevance—Results of this study document the implementation of recommendations by several authors in veterinary texts that antimicrobial drugs be administered perioperatively in equine patients with colic that are undergoing surgery. However, the need for long-term antimicrobial drug treatment in equine patients with colic is unknown. (J Am Vet Med Assoc 2002;220:1359–1365)

Abstract

Objective—To evaluate antimicrobial susceptibility of commensal Escherichia coli strains isolated from the feces of horses and investigate relationships with hospitalization and antimicrobial drug (AMD) administration.

Design—Observational study.

Animals—68 hospitalized horses that had been treated with AMDs for at least 3 days (HOSP–AMD group), 63 hospitalized horses that had not received AMDs for at least 4 days (HOSP–NOAMD group), and 85 healthy horses that had not been hospitalized or treated with AMDs (community group).

Procedures—Fecal samples were submitted for bacterial culture, and up to 3 E coli colonies were recovered from each sample. Antimicrobial susceptibility of 724 isolates was evaluated. Prevalence of resistance was compared among groups by use of log-linear modeling.

Results—For 12 of the 15 AMDs evaluated, prevalence of antimicrobial resistance differed significantly among groups, with prevalence being highest among isolates from the HOSP–AMD group and lowest among isolates from the community group. Isolates recovered from the HOSP–AMD and HOSP–NOAMD groups were also significantly more likely to be resistant to multiple AMDs. Resistance to sulfamethoxazole and resistance to trimethoprim-sulfamethoxazole were most common, followed by resistance to gentamicin and resistance to tetracycline. Use of a potentiated sulfonamide, aminoglycosides, cephalosporins, or metronidazole was positively associated with resistance to 1 or more AMDs, but use of penicillins was not associated with increased risk of resistance to AMDs.

Conclusion and Clinical Relevance—Results suggest that both hospitalization and AMD administration were associated with prevalence of antimicrobial resistance among E coli strains isolated from the feces of horses.

Abstract

Objective—To develop a questionnaire for self-assessment of biosecurity practices at equine boarding facilities and to evaluate infectious disease control practices in these facilities in Colorado.

Design—Cross-sectional study.

Sample Population—64 equine boarding facilities in Colorado.

Procedures—Survey questions were rated according to importance for prevention and containment of equine infectious diseases. Point values (range, 0 to 20) were assigned for possible responses, with greater values given for optimal infection control methods. Questionnaires were mailed to equine boarding facilities in Colorado advertised on the World Wide Web. Survey responses were compared with assessments made by a member of the research team during visits to 30 randomly selected facilities. Agreement among results was analyzed via a kappa test and rated as poor, fair, moderate, substantial, or nearly perfect.

Results—Survey responses were received for 64 of 163 (39%) equine boarding facilities. Scores ranged from 106 to 402 points (maximum possible score, 418). Most facilities received better scores for movement and housing of equids than for other sections of the survey. Respondents at 24 of 48 (50%) facilities that routinely received new equids reported isolation of new arrivals. Agreement between self-assessment by survey respondents and evaluation by a member of the research team was determined to be fair to substantial.

Conclusions and Clinical Relevance—Most equine boarding facilities have opportunities to improve measures for prevention or containment of contagious diseases (eg, isolation of newly arrived equids and use of written health management protocols). Most self-assessments of infection control practices were accurate.

Abstract

Objective—To determine the adsorptive capability of di-tri-octahedral smectite (DTOS) on Clostridium perfringens alpha, beta, and beta-2 exotoxins and equine colostral antibodies.

Sample Population—3 C perfringens exotoxins and 9 colostral samples.

Procedures—Alpha, beta, and beta-2 exotoxins were individually co-incubated with serial dilutions of DTOS or bismuth subsalicylate, and the amount of toxin remaining after incubation was determined via toxin-specific ELISAs. Colostral samples from healthy mares were individually co-incubated with serial dilutions of DTOS, and colostral IgG concentrations were determined via single radial immunodiffusion assay.

Results—Di-tri-octahedral smectite decreased the amount of each C perfringens exotoxin in co-incubated samples in a dose-dependent manner and was more effective than bismuth subsalicylate at reducing exotoxins in vitro. Decreases in the concentration of IgG were detected in samples of colostrum that were combined with DTOS at 1:4 through 1:16 dilutions, whereas no significant decrease was evident with DTOS at the 1:32 dilution.

Conclusions and Clinical Relevance—Di-tri-octahedral smectite effectively adsorbed C perfringens exotoxins in vitro and had a dose-dependent effect on the availability of equine colostral antibodies. Results suggested that DTOS may be an appropriate adjunctive treatment in the management of neonatal clostridiosis in horses. In vivo studies are necessary to fully assess the clinical efficacy of DTOS treatment.

Abstract

Objective—To identify factors associated with development of vesicular stomatitis (VS).

Design—Case-control study.

Sample Population—138 livestock premises and 118 horses suspected of having VS in Texas, New Mexico, and Colorado.

Procedures—Premises with ≥ 1 animal with clinical signs and laboratory confirmation of infection were classified as case premises. Premises where laboratory confirmation results were negative were control premises. Among equine premises, case and control horses were selected on the basis of premises status. A survey was conducted to identify factors associated with VS for premises and specific horses.

Results—Control of insect populations in the 2 weeks before the VS investigation decreased the odds of disease for premises where vegetation coverage was grassland or pasture (odds ratio [OR], 0.08; 95% confidence interval [CI], 0.01 to 0.7). Odds of VS for premises covered with grassland or pasture increased when measures to control insect populations were not used (OR, 11; 95% CI, 0.8 to 156.3) and for premises that had a body of water (OR, 2.3; 95% CI, 1.0 to 5.6). Use of measures to prevent insect bites or harassment by insects (OR, 0.2; 95% CI, 0.1 to 0.8) and spending time in shelters (OR, 0.4; 95% CI, 0.2 to 1.1) in the 2 weeks prior to investigation decreased the odds of being a case horse.

Conclusions and Clinical Relevance—Insect control and spending time in shelters decreased the odds for infection with VS. Premises covered with grassland or pasture or that had a body of water were at a higher risk.

Abstract

Objective—To compare temperature readings from an implantable percutaneous thermal sensing microchip with temperature readings from a digital rectal thermometer, to identify factors that affect microchip readings, and to estimate the sensitivity and specificity of the microchip for fever detection.

Design—Prospective study.

Animals—52 Welsh pony foals that were 6 to 10 months old and 30 Quarter Horses that were 2 years old.

Procedures—Data were collected in summer, winter, and fall in groups 1 (n = 23 ponies), 2 (29 ponies), and 3 (30 Quarter Horses), respectively. Temperature readings from a digital rectal thermometer and a percutaneous thermal sensing microchip as well as ambient temperature were recorded daily for 17, 23, and 19 days in groups 1 through 3, respectively. Effects of ambient temperature and rectal temperature on thermal sensor readings were estimated. Sensitivity and specificity of the thermal sensor for detection of fever (rectal temperature, ≥ 38.9°C [102°F]) were estimated separately for data collection at ambient temperatures ≤ 15.6°C (60°F) and > 15.6°C.

Results—Mean ambient temperatures were 29.0°C (84.2°F), −2.7°C (27.1°F), and 10.4°C (50.8°F) for groups 1 through 3, respectively. Thermal sensor readings varied with ambient temperature and rectal temperature. Rectal temperatures ranged from 36.2° to 41.7°C (97.2° to 107°F), whereas thermal sensor temperature readings ranged from 23.9° (75°F) to 42.2°C (75° to 108°F). Sensitivity for fever detection was 87.4%, 53.3%, and 58.3% in groups 1 to 3, respectively.

Conclusions and Clinical Relevance—The thermal sensor appeared to have potential use for initial screening of body temperature in equids at ambient temperatures > 15.6°C.

Abstract

Objective—To use real-time polymerase chain reaction (PCR) technology to develop a highly sensitive and specific diagnostic assay for the detection of Salmonella spp in fecal specimens.

Sample Population—299 fecal specimens from cattle, horses, and dogs.

Procedure—Enrichment of fecal specimens was followed by genomic DNA extraction by use of commercially available isolation kits. Real-time PCR assay was performed to target a Salmonella spp-specific DNA segment. Results of real-time PCR assay were compared with bacterial culture results to determine relative sensitivity and specificity.

Results—Use of the spaQ primer-probe set resulted in a relative sensitivity of 100% and a specificity of 98.2%, compared with bacterial culture results when tested on 299 clinical fecal specimens.

Conclusion and Clinical Relevance—A rapid, sensitive, and specific assay for the detection of Salmonella spp from enriched clinical fecal specimens was developed. This technique would be highly valuable in clinical settings to help avoid or mitigate the complications arising from an outbreak of salmonellosis in a herd or among patients of a veterinary hospital. (Am J Vet Res 2002;63:1265–1268)

Abstract

Objective—To evaluate the prevalence of nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA) in horses and horse personnel.

Design—Prospective prevalence study.

Sample Population—972 horses and 107 personnel from equine farms in Ontario, Canada and New York state.

Procedure—Nasal swab specimens were collected from horses and humans on farms with (targeted surveillance) and without (nontargeted surveillance) a history of MRSA colonization or infection in horses during the preceding year. Selective culture for MRSA was performed. Isolates were typed via pulsed-field gel electrophoresis, and antibiograms were determined.

Results—MRSA was isolated from 46 of 972 (4.7%) horses (0/581 via nontargeted surveillance and 46/391 [12%] via targeted surveillance). Similarly, MRSA was isolated from 14 of 107 (13%) humans (2/41 [5%] from nontargeted surveillance and 12/66 [18%] from targeted surveillance). All isolates were subtypes of Canadian epidemic MRSA-5, an uncommon strain in humans. All isolates were resistant to at least 1 antimicrobial class in addition to β-lactams. On all farms with colonized horses, at least 1 human was colonized with an indistinguishable subtype. For horses, residing on a farm that housed > 20 horses was the only factor significantly associated with MRSA colonization. For humans, regular contact with > 20 horses was the only identified risk factor.

Conclusions and Clinical Relevance—Results confirm a reservoir of colonized horses on a variety of farms in Ontario and New York and provide evidence that 1 MRSA strain is predominantly involved in MRSA colonization in horses and humans that work with horses. (J Am Vet Med Assoc 2005;226:580–583)

Abstract

Objective—To determine historical, physical examination, clinicopathologic, and postmortem findings in horses with putative uremic encephalopathy.

Design—Retrospective study.

Animals—5 horses with renal failure and neurologic disease not attributable to abnormalities in any other organ system.

Procedure—Medical records from 1978 to 1998 were examined for horses with renal disease and neurologic signs not attributable to primary neurologic, hepatic, or other diseases. Signalment, history, physical examination findings, clinicopathologic data, renal ultrasonographic findings, and postmortem data were reviewed.

Results—Of 332 horses with renal disease, 5 met selection criteria. Historical findings, physical examination findings, clinicopathologic data, ultrasonographic data, and postmortem findings were consistent with chronic renal failure. Swollen astrocytes were detected in all 4 horses examined at necropsy.

Conclusions and Clinical Relevance—A single criterion was not determined to be pathognomonic for uremic encephalopathy in horses. Uremic encephalopathy should be considered as a differential diagnosis in horses with evidence of chronic renal failure and encephalopathic neurologic sign not attributable to other causes. Astrocyte swelling, which was common to all 4 horses examined at necropsy, may serve as a microscopic indicator of uremic encephalopathy in horses. (J Am Vet Med Assoc 2001;218:560–566)

Abstract

Objective—To evaluate factors potentially associated with fecal Salmonella shedding among equine patients hospitalized for colic at a veterinary teaching hospital and to determine the effects of probiotic treatment on fecal Salmonella shedding and clinical signs.

Design—Longitudinal study and controlled trial.

Animals—246 equine colic patients.

Procedure—History and medical information were obtained from patient records. Fecal and environmental samples were submitted for aerobic bacterial culture for Salmonella enterica. Fifty-one patients were treated with a commercially available probiotic; 46 were treated with a placebo. Logistic regression was used to evaluate data.

Results—Salmonella organisms were detected in feces from 23 (9%) patients at least once during hospitalization. Patients were more likely to shed Salmonella organisms if diarrhea was evident ≤ 6 hours after hospitalization and duration of hospitalization exceeded 8 days (odds ratio [OR], 20.3), laminitis developed during hospitalization (OR, 12.0), results of nasogastric intubation were abnormal (OR, 4.9), leukopenia was evident ≤ 6 hours after hospitalization (OR, 4.6), or travel time to the teaching hospital exceeded 1 hour (OR, 3.5). Horses treated with the probiotic did not differ from control horses in regard to likelihood of fecal Salmonella shedding (OR, 1.5) or prevalence of clinical signs.

Conclusions and Clinical Relevance—Results suggest that certain risk factors are associated with fecal shedding of S enterica among equine patients hospitalized at a veterinary teaching hospital because of colic and that pathogen monitoring in patients and the hospital environment and use of barrier nursing precautions for equine colic patients are beneficial. (J Am Vet Med Assoc 2001;218:740–748)