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Summary

A study of data from 12 states in the Food Safety Inspection Service’s Residue Violation Information System was conducted to describe patterns of violative chemical residues in US beef during 1991, 1992, and 1993. In 1991, 3,249 violative residues were found in 2,734 carcasses in the 12 states included in the study. In 1992, 3,132 violative residues were found in 2,813 carcasses, and in 1993, 2,317 violative residues were found in 2,051 carcasses. During each of the 3 years, the Calf Antibiotic and Sulfonamide Test and Swab Test On Premises projects detected most of the violative residues, and producers/independent growers and dairy farms were recorded as the responsible sources for most of the violations. Also, most of the animals found to have violative residues were bob calves and culled cows. In bob calves, neomycin was the most frequently identified violative chemical, followed by tetracycline, gentamicin, Oxytetracycline, and penicillin. In culled cows, penicillin was the most frequently identified violative chemical and was the chemical most frequently found in combination with other chemicals in cows with multiple violative residues. Distribution patterns of violative chemical residues by slaughter class and residue type varied among the 5 Food Safety Inspection Service regions. These specific regional characteristics support the need for customized intervention, education, assessment, and prevention programs.

Free access
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Abstract

Objective—To gain a better understanding of the role of interpersonal trust in veterinarian-client interactions during routine health-care visits, develop a measure of trust uniquely suited to the context of veterinary medicine, and interpret the actions, beliefs, and perceptions that capture client trust toward veterinarians.

Design—Correlational study.

Sample—103 veterinary students and 19 standardized clients with pets from a college of veterinary medicine at a large public Midwestern university.

Procedures—A measure of trust specific to veterinarian-client interactions was constructed on the basis of preexisting conceptualizations of the construct and administered to veterinary students and standardized clients following interactions in 2 medical scenarios in a high-fidelity simulated animal health clinic. Exploratory and confirmatory factor analytic techniques were used to validate the measure of trust, and hierarchic linear modeling was used to explore indicators of standardized client trust perceptions in one of the scenarios.

Results—Factor analysis revealed that the measure captured 2 perceptions indicative of trust in veterinary contexts: professionalism and technical candor. Students who had behaviors reflecting these factors as well as those who were perceived as more technically competent were seen as more trustworthy by standardized clients.

Conclusions and Clinical Relevance—The development of trustworthy relationships between clients and veterinarians is important to the continued growth and success of the profession. By identifying characteristics of veterinarian trustworthiness and developing related measurement tools, proactive approaches to monitoring veterinarian-client relations can be implemented and incorporated into veterinary training and practice programs to identify areas for improvement.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To compare endoscopic findings of the upper portion of the respiratory tract in Thoroughbred yearlings with their subsequent race records to determine whether subjective assessment of airway function may be used as a predictor of future racing performance.

Design—Retrospective study.

Animals—427 Thoroughbred yearlings.

Procedures—Endoscopic examination findings were obtained from the medical records and the videoendoscopic repository of the Keeneland 1996 September yearling sales. Racing records were requested for the yearlings through the end of their 4-year-old racing season (1997–2000). Twenty-nine measures of racing performance were correlated with endoscopic findings. Subjective arytenoid cartilage movement grades were determined, using a 4-point grading scale (grade 1 = symmetrical synchronous abduction of the arytenoid cartilages; grade 4 = no substantial movement of the left arytenoid cartilage).

Results—Of the 427 Thoroughbred yearlings included in this study, 364 established race records, and 63 did not. Opinions regarding suitability for purchase, meeting conditions of the sale, and the presence of epiglottic abnormalities had no significant association with racing performance. Arytenoid cartilage movement grades were significantly associated with many of the dependent variables. However, palatine abnormalities were not predictive of inferior racing performance.

Conclusions and Clinical Relevance—Thoroughbred yearlings with grade-1 and -2 arytenoid cartilage movements had significantly better racing performance as adults, compared with yearlings with grade- 3 arytenoid cartilage movements. In contrast, epiglottic and palatine abnormalities were not predictive of inferior racing performance. Therefore, evaluation of laryngeal function, but not epiglottic or palatine abnormalities, using the 4-point grading system, should be the major factor in developing recommendations for prospective buyers. (J Am Vet Med Assoc 2001;219: xxx–xxx)

Full access
in Journal of the American Veterinary Medical Association

SUMMARY

Objective

To evaluate the influence of exogenous hyaluronan (HA) on in vitro synthesis of HA and collagenase by equine synoviocytes from normal and inflamed joints.

Animals

9 adult horses.

Procedure

Synoviocytes for culture were taken from the middle carpal joint of 3 horses with normal joints (control) and 6 horses with osteochondral fractures (principal). Synoviocytes were propagated in monolayer cultures and were incubated with 3 commercial HA products at concentrations of 0, 200, 400, and 1,500 μg/ml. Newly synthesized HA was radiolabeled with [3H]glucosamine and quantified by cetylpyridinium chloride precipitation and liquid scintillation counting. The hydrodynamic size of radioactive HA was determined by high-performance liquid chromatography, and collagenase activity was evaluated by use of a quantitative radioactive collagen film assay.

Results

Exogenous HA influenced neither the rate of synthesis nor the hydrodynamic size of the newly produced HA by control or principal cell cultures. Culture supernatants from abnormal synovium, exposed to 400 and 1,500 μg of exogenous HA/ml, contained significantly more collagenase activity than did those exposed to lower concentrations.

Conclusion

Although HA is thought to have beneficial effects in equine arthropathies, the principal mechanisms of action of HA do not appear to be stimulation of synthesis of HA of augmented molecular weight or marked inhibition of collagenase synthesis. (Am J Vet Res 1998;59:888–892)

Free access
in American Journal of Veterinary Research

Abstract

Objective—To determine the likelihood of false-positive results when testing milk samples from individual cows by use of 3 commercially available assays (Penzyme Milk Test and the SNAP β-lactamand Delvo- SP assays) labeled for use with commingled milk.

Sample Population—Milk samples from 111 cows with mild clinical mastitis.

Procedure—Cows were randomly assigned to the control (no antimicrobials) or intramammary treatment group. Posttreatment milk samples were collected at the first milking after the labeled withholding period or an equivalent time for controls, randomly ordered, and tested twice by use of each assay and once by use of high-performance liquid chromatography. Sensitivity, specificity, and positive and negative predictive values were determined for each assay. Concordance of results for the same sample was assessed for each assay by calculating κ.

Results—Sensitivities of the Delvo-SP and SNAP β-lactam assays were > 90%, whereas the sensitivity of the Penzyme Milk Test was 60%. Positive predictive values (range, 39.29 to 73.68%) were poor for all 3 assays. Concordance of test results was excellent for the SNAP β-lactam and Delvo-SP assays (κ = 0.846 and 0.813, respectively) but was less for the Penzyme Milk Test (κ = 0.545).

Conclusions and Clinical Relevance—Because of the low positive predictive values, these 3 assays may not be useful for detecting violative antimicrobial residues in individual milk samples from cows treated for mild clinical mastitis. However, repeatability of each assay was considered good to excellent. (Am J Vet Res 2001;62:1716–1720)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To characterize potential mechanisms of action of glucosamine inhibition of matrix metalloproteinase (MMP) expression and activity in lipopolysaccharide (LPS)-stimulated equine chondrocytes.

Sample Population—Chondrocytes cultured from samples of metacarpophalangeal articular cartilage collected from cadaveric limbs of horses.

Procedure—The effect of glucosamine on MMP activity in conditioned medium from LPS-stimulated cartilage explants was determined by a colorimetric assay with azocoll substrate. Treatments consisted of negative and positive controls, glucose (50mM), and glucosamine (50, 25, 6.25, 3, and 1.5mM). The influence of glucosamine on MMP synthesis was determined in chondrocytes in pellet culture incubated with LPS (20 µg/mL). Concentration of MMP-13 was quantified in spent medium via ELISA; nonspecific MMP activity was determined via azocoll digestion in organomercurial- activated medium. Effects of glucosamine on MMP mRNA concentration in similarly treated chondrocytes were determined by northern blot hybridization with MMP-1, -3, and -13 probes. Statistical analyses were performed with 2-way ANOVA.

Results—Glucosamine had no effect on activated MMP activity but inhibited MMP protein expression, as determined by azocoll digestion (glucosamine, 3 to 50mM) and MMP-13 ELISA (glucosamine, 1.5 to 50mM). Resting mRNA concentrations for MMP-1, -3, and -13 mRNA were significantly lower in cultures exposed to glucosamine at concentrations of 50 and 25mM than those of positive controls.

Conclusions and Clinical Relevance—Glucosamine appears capable of pretranslational, and possibly also translational, regulation of MMP expression; data suggest a potential mechanism of action for chondroprotective effects of this aminomonosaccharide. ( Am J Vet Res 2003;64:666–671)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To test the hypothesis that dairy farms certified in the Milk and Dairy Beef Quality Assurance Program (QAP) were more likely to use prudent drug management practices than farms that were not certified.

Design—Cross-sectional study.

Sample Population—141 Michigan dairy farms of which 74 were not certified in the QAP, 30 were involuntarily certified, and 37 were voluntarily certified.

Procedure—Dairy producers completed a self-administered questionnaire that focused on herd health management, drug use, record keeping, personnel management, and descriptive characteristics of their farm during 1993. Separate multivariable logistic regression models were developed to determine the association of QAP certification with each of the management practices.

Results—Results suggested that farms adopted specific management practices irrespective of certification. Many farms used visible identification and nonemergency veterinary services and discussed residue prevention with employees. Involuntary certification was associated with maintenance of good written treatment records and performance of on-farm drug residue testing. Voluntary certification was weakly associated with use of refrigerated drug storage.

Conclusions and Clinical Relevance—QAP certification appeared to have been associated with the adoption of only a few prudent drug use practices, although QAP materials and framework were developed to assist veterinarians in the promotion of disease prevention, client communication, and residue prevention practices on farms. Veterinary care would benefit from the development and encouragement of better record keeping on farms. (J Am Vet Med Assoc 2000;216:1960–1964)

Full access
in Journal of the American Veterinary Medical Association