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in Journal of the American Veterinary Medical Association

Summary

Hyperlipemic serum and plasma samples often are received by clinical laboratories for endocrinologic analysis by radioimmunoassay. We designed a study to determine what effect, if any, hyperlipemia has on estimation of lipid-soluble hormone concentrations determined by solid-phase radioimmunoassays. Progesterone, testosterone, thyroxine, and cortisol concentrations were determined in canine plasma and serum with various degrees of lipemia. Samples of serum, heparinized plasma, and edta-treated plasma were obtained from blood collected from 4 female and 4 male Beagles by use of evacuated tubes. To induce hyperlipemia in vitro, iv fat emulsion was diluted in deionized water to produce 0 (water only), 33, 67, or 100% mixtures. Twenty microliters of each mixture then was added to the subsamples of serum and plasma from each dog. Hormone concentrations were determined, using validated radioimmunoassays. Triglyceride concentrations were determined by enzymatic assay. Addition of iv fat emulsion in vitro was an accurate and reproducible means of altering triglyceride concentrations in the samples. Triglyceride concentrations as high as 700 mg/dl had no effect on radioimmunoassays for progesterone, testosterone, and thyroxine in serum, heparinized plasma, or edta-treated plasma. Addition of 100% (but not 33 or 67%) fat emulsion reduced the mean cortisol concentration in heparinized plasma by 12% (P < 0.05). This severe hyperlipemia did not affect quantification of cortisol in serum or edta-treated plasma.

Free access
in American Journal of Veterinary Research

Summary

A dairy farm located in central New York was visited because of complaints of electrical shock in the farmhouse shower and the milk house sink. As much as 2 volts AC of potential difference was measured between the waterline and the cow platform (cow-contact voltage). Voltage was coming from the primary neutral wire. The farm's electrical service was modified so that the farmstead could be connected or disconnected from the primary neutral wire at 2-week intervals for 12 weeks. When connected to the primary neutral wire, voltage between waterline and floor ranged between 0 and 1.8 volts, producing estimated current flow through cows of 3.6 to 4.9 mA; when disconnected from primary neutral wire, voltage between waterline and floor was < 0.1 volt. There was no difference in mean milk production, bulk tank milk somatic cell count, or water consumption among periods when cows were exposed or unexposed to voltage. Despite statistical nonsignificance, the values for somatic cell count were lower and water consumption was higher when cows were exposed to voltage than when they were not.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To compare pharmacokinetic and pharmacodynamic characteristics of fentanyl citrate after IV or transdermal administration in cats.

Animals—6 healthy adult cats with a mean weight of 3.78 kg.

Procedure—Each cat was given fentanyl IV (25 mg/cat; mean ± SD dosage, 7.19 ± 1.17 mg/kg of body weight) and via a transdermal patch (25 µg of fentanyl/h). Plasma concentrations of fentanyl were measured by use of radioimmunoassay. Pharmacokinetic analyses of plasma drug concentrations were conducted, using an automated curvestripping process followed by nonlinear, leastsquares regression. Transdermal delivery of drug was calculated by use of IV pharmacokinetic data.

Results—Plasma concentrations of fentanyl given IV decreased rapidly (mean elimination half-life, 2.35 ± 0.57 hours). Mean ± SEM calculated rate of transdermal delivery of fentanyl was 8.48 ± 1.7 mg/h (< 36% of the theoretical 25 mg/h). Median steadystate concentration of fentanyl 12 to 100 hours after application of the transdermal patch was 1.58 ng/ml. Plasma concentrations of fentanyl < 1.0 ng/ml were detected in 4 of 6 cats 12 hours after patch application, 5 of 6 cats 18 and 24 hours after application, and 6 of 6 cats 36 hours after application.

Conclusions and Clinical Relevance—In cats, transdermal administration provides sustained plasma concentrations of fentanyl citrate throughout a 5- day period. Variation of plasma drug concentrations with transdermal absorption for each cat was pronounced. Transdermal administration of fentanyl has potential for use in cats for long-term control of pain after surgery or chronic pain associated with cancer. (Am J Vet Res 2000;61:672–677)

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in American Journal of Veterinary Research

Abstract

Objective—To compare the trotting gaits of Labrador Retrievers and Greyhounds to determine whether differences in locomotion are attributable to differences in their manner of moving or to body size and shape differences between these 2 breeds.

Animals—8 healthy 5-month-old Greyhounds and 5 healthy Labrador Retrievers between 6 and 18 months old.

Procedure—A series of 4 force platforms was used to record independent ground reaction forces on the forelimbs and hind limbs during trotting. Values of stride parameters were compared between breeds before and after normalization for size differences. Standard values of absolute and normalized stride period and stride length were determined from linear regressions of these parameters on relative (normalized) velocity. Forces were normalized to body weight and compared at the same relative velocity.

Results—Greyhounds used fewer, longer strides than the Labrador Retrievers to travel at the same absolute speed. After normalization for body size differences, most measurable differences between breeds were eliminated. Subtle differences that did persist related to proportion of the stride that the forefoot was in contact with the ground, timing of initial hind foot contact relative to initial forefoot contact, and distribution of vertical force between the forelimbs and hind limbs.

Conclusions and Clinical Relevance—Results suggest that apparent differences in the trotting gait between Labrador Retrievers and Greyhounds are mainly attributable to differences in size, and that dogs of these 2 breeds move in a dynamically similar manner at the trot. (Am J Vet Res 2000;61: 832–838)

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in American Journal of Veterinary Research

Abstract

Objective—To genetically type Campylobacter jejuni isolates from broiler houses or the external environment to identify the source of Campylobacter organisms in broiler chickens.

Sample Population—Environmental samples associated with broiler chickens, in commercial grow-out houses.

Procedure—Polymerase chain reaction (PCR) was used to amplify flaB, and the amplicon was digested with Sau3A to create a restriction fragment length polymorphism assay; PCR was also used to detect a transcribed spacer region in the 23S rRNA gene.

Results—Isolates possessing a 23S spacer region were more prevalent outside broiler houses than inside. Houses that had previously contained chickens or lacked biosecurity procedures were more likely to contain isolates possessing the 23S spacer. One house contained only isolates possessing the spacer, whereas an adjacent house contained only isolates lacking the spacer. The flaB type detected in broiler houses was different from the type detected in the environment; however, many isolates within the broiler houses contained untypable flaB genotypes.

Conclusions and Clinical Relevance—Most isolates from within houses were genetically distinct from isolates from outside houses that were examined by bacteriologic culture, suggesting an undetected source of C jejuni. Detection of isolates containing the 23S spacer appeared to be an indicator of environmental contamination of the houses. The observation of completely different C jejuni genetic types simultaneously within adjacent houses suggests that some types do not compete successfully during the grow-out period. In addition, the diversity of genotypes identified within broiler houses indicates the complexity of the ecologic features of C jejuni in the chicken environment. (Am J Vet Res 2001;62:190–194)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To investigate individual- and community-level contextual variables as risk factors for submission of calcium oxalate (CaOx) uroliths or magnesium ammonium phosphate (ie, struvite) uroliths for dogs to a national urolith center, as determined on the basis of urolith submission patterns.

Sample Population—Records of 7,297 dogs from Ontario, Canada, with CaOx or struvite uroliths submitted to the Canadian Veterinary Urolith Centre from 1998 through 2006.

Procedures—Data were analyzed via multilevel multivariable logistic regression.

Results—Individual-level main effects and interactions significantly associated with the risk of submission of CaOx uroliths rather than struvite uroliths included age, sex, breed group, neuter status, body condition, dietary moisture content, diet type, sex-neuter status interaction, sex-age interaction, body condition-age interaction, and breed group—dietary moisture content interaction. In addition, median community family income and being located within a major urban center (ie, Toronto) were significant risk factors for submission of CaOx uroliths, compared with submission of struvite uroliths.

Conclusions and Clinical Relevance—Individual-level and dietary factors for dogs affected the risk of submission of CaOx uroliths, relative to that of struvite uroliths. Interactions among these variables need to be considered when assessing the impact of these risk factors. In addition, community-level or contextual factors (such as community family income and residing in a densely populated area of Ontario) also affected submission patterns, although most of the variance in the risk for submission of CaOx uroliths, compared with the risk for submission of struvite uroliths, was explained by individual-level factors. (Am J Vet Res 2010;71:1045–1054)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To develop an in vitro model of cartilage injury in full-thickness equine cartilage specimens that can be used to simulate in vivo disease and evaluate treatment efficacy.

Sample—15 full-thickness cartilage explants from the trochlear ridges of the distal aspect of the femur from each of 6 adult horses that had died from reasons unrelated to the musculoskeletal system.

Procedures—To simulate injury, cartilage explants were subjected to single-impact uniaxial compression to 50%, 60%, 70%, or 80% strain at a rate of 100% strain/s. Other explants were left uninjured (control specimens). All specimens underwent a culture process for 28 days and were subsequently evaluated histologically for characteristics of injury and early stages of osteoarthritis, including articular surface damage, chondrocyte cell death, focal cell loss, chondrocyte cluster formation, and loss of the extracellular matrix molecules aggrecan and types I and II collagen.

Results—Compression to all degrees of strain induced some amount of pathological change typical of clinical osteoarthritis in horses; however, only compression to 60% strain induced significant changes morphologically and biochemically in the extracellular matrix.

Conclusions and Clinical Relevance—The threshold strain necessary to model injury in full-thickness cartilage specimens from the trochlear ridges of the distal femur of adult horses was 60% strain at a rate of 100% strain/s. This in vitro model should facilitate study of pathophysiologic changes and therapeutic interventions for osteoarthritis.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine the lowest dose of cosyntropin on a per body weight basis that would produce maximal cortisol and aldosterone secretion and the ideal timing of blood sample collection after ACTH stimulation in healthy cats.

Design—Randomized crossover trial.

Animals—7 adult sexually intact male purpose-bred cats.

Procedures—Each cat received saline (0.9% NaCl) solution (control) and 5 doses (125 μg/cat and 10, 5, 2.5, and 1 μg/kg [4.54, 2.27, 1.14, and 0.45 μg/lb]) of cosyntropin IV with a 2-week washout period between treatments. Blood samples were obtained before (baseline) and at 15, 30, 45, 60, 75, and 90 minutes after administration of saline solution or cosyntropin.

Results—Serum cortisol and aldosterone concentration increased significantly, compared with baseline values, after administration of all cosyntropin doses. Lower doses of cosyntropin resulted in an adrenocortical response equivalent to the traditional dose of 125 μg/cat. The lowest doses of cosyntropin that stimulated a maximal cortisol and aldosterone response were 5 and 2.5 μg/kg, respectively. Lower doses of cosyntropin resulted in a shorter interval between IV administration of cosyntropin and peak serum cortisol and aldosterone concentrations.

Conclusions and Clinical Relevance—Low-dose ACTH stimulation testing with IV administration of cosyntropin at 5 μg/kg followed by blood sample collection at 60 to 75 minutes resulted in concurrent peak serum cortisol and aldosterone concentrations that were equivalent to those achieved following administration of cosyntropin at 125 μg/cat, the standard dose currently used.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To assess student awareness of the financial costs of pursuing a veterinary education, to determine student expectations for financial returns of a veterinary career, and to identify associations between student debt and factors such as future career plans or personality type.

Design—Survey.

Sample—First-year veterinary students at the University of Minnesota College of Veterinary Medicine.

Procedures—In 2013, prior to the first day of class, all incoming first-year students received an email invitation to complete an online survey. The survey contained questions about demographics, current financial situation, current debt, expected debt at graduation, expected annual income following graduation, intent to pursue specialty training, and Myers-Briggs personality type.

Results—72 of 102 (71%) students completed the survey; 65 respondents answered all relevant questions and provided usable data. Student responses for expected debt at graduation were comparable to national averages for veterinary college graduates; responses for expected annual income following graduation were lower than averages for University of Minnesota veterinary college graduates and national averages. However, students predicted even lower annual income if they did not attend veterinary college. Expected debt and expected annual income were not correlated with factors such as personality type or future career plans.

Conclusions and Clinical Relevance—Results indicated that first-year veterinary students were aware of the financial costs of their veterinary education and had realistic expectations for future salaries. For typical veterinary students, attending veterinary college appeared to be financially worthwhile, given lower expected earnings otherwise. (J Am Vet Med Assoc 2015;247:196–203)

Full access
in Journal of the American Veterinary Medical Association