bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of injury to the suspensory apparatus, exercise, and horseshoe characteristics on the risk of lateral condylar fracture and suspensory apparatus failure in forelimbs of Thoroughbred racehorses
Authors: Hill Ashley E. , Gardner Ian A. , Carpenter Tim E. , Stover Susan M. 
Published: December 2005

AbstractObjective—To assess concurrently the effects of moderate ligamentous suspensory apparatus injury (MLSAI), racing-speed exercise, and horseshoe characteristics on risk of catastrophic suspensory apparatus failure (SAF) or metacarpal condylar fracture (CDY) in forelimbs of racehorses.Sample population—Cadavers of 301 Thoroughbred racehorses (108 with SAF, 33 with CDY, and 160 control horses).Procedure—A cross-sectional epidemiologic study was used to describe distributions and relationships between MLSAI, exercise, and horseshoe variables. Logistic regression was used to assess potential risk factors for developing SAF and CDY.Results—Exercise variables were more highly associated with age than height of a steel bar affixed to the ground surface of the front of a horseshoe (ie, toe grab) or sex. Marginal associations were detected between MLSAI and age and height of toe grab. Higher risk for developing SAF was associated with MLSAI, use of a pad on a horseshoe, longer interval since last period of ≥ 60 days without a race or timed workout (ie, layup), 2 to 5 career races, and higher intensity of recent exercise. Higher risk for developing CDY was associated with MLSAI, male horses, age between 2 and 5 years, higher intensity of recent exercise, and longer interval since layup.Conclusions and Clinical Relevance—Recognition of MLSAI and rehabilitation of affected horses should reduce incidence of SAF and CDY. Horses in long-term continuous training with recent high-intensity exercise are at greater risk for injury. Use of pads in horseshoes was associated with SAF, although the relationship may not be causal. (Am J Vet Res2004;65:1508–1517).
Microbiologic findings in feedlot cattle with acute interstitial pneumonia
Authors: Woolums Amelia R. , Mason Gary L. , Hawkins Larry L. , Brown Corrie C. , Williams Shamita M. , Gould Jared A. , Fox Jocelyn J. , Sturgeon Scott D. , Anderson Jenny L. , Duggan Florence E. , Sanchez Susan , Barrett Paula B. , Chitwood Sharon W. 
Published: December 2005

AbstractObjective—To test the hypothesis that feedlot cattle with acute interstitial pneumonia (AIP) have bacterial infection of the lung or liver and concurrent bovine respiratory syncytial virus (BRSV) infection significantly more often than pen mates without AIP.Animals—39 feedlot cattle with signs consistent with AIP and no history of treatment with antimicrobials and 32 healthy control cattle from the same pens.Procedure—Lung and liver specimens were obtained postmortem for bacterial or mycoplasmal culture and histologic examination; lung tissue was assessed for BRSV infection immunohistochemically.Results—Among affected cattle, 26 had AIP confirmed histologically. Lung tissue from 11 cattle with AIP yielded microbial respiratory tract pathogens on culture; tissues from control animals yielded no microbial growth. In 4 cattle with AIP and 2 control animals, liver abscesses were detected; bacteria were isolated from abscessed tissue in 3 and 1 of those animals, respectively. Immunohistochemically, 9 cattle with AIP and no control animals were BRSV-positive. Histologically, 9 AIP-affected cattle had only acute alveolar damage with exudation, and the other 17 had acute exudation with type II pneumocyte hyperplasia. No lesions of AIP were detected in control animals. Only 4 AIP-affected cattle had bacterial infection of the lung with concurrent BRSV infection.Conclusions and Clinical Relevance—Results indicated that microbial respiratory tract pathogens are more common in cattle with AIP than in healthy pen mates. Control of bacterial pneumonia late in the feeding period may reduce the incidence of AIP at feedlots where AIP is a problem. (Am J Vet Res2004;65:1525–1532)
Pharmacokinetic-pharmacodynamic relationships and dose response to meloxicam in horses with induced arthritis in the right carpal joint
Authors: Toutain Pierre-Louis , Cester Corinne C. 
Published: December 2005

Abstract

Objective—To determine pharmacokinetic-pharmacodynamic
(PK-PD) relationships and dose effects for
meloxicam in horses and to propose a suitable
dosage for use in clinical studies.

Animals—6 adult horses.

Procedure—The study was conducted by use of a
randomized, Latin-square design. Arthritis was
induced in the right carpal joint of each horse by
administration of Freund's complete adjuvant. Various
dosages of meloxicam (0, 0.25, 0.5, 1.0, and
2.0 mg/kg, IV) were then administered. Validated endpoints
including stride length and overall clinical lameness
score (scale of 0 to 20) were used to assess the
effect of meloxicam. The dose-effect relationship was
quantified by use of a maximum possible effect
(Emax) model.

Results—For stride length (expressed as a relative
percentage increase from control values), the median
effective dose (ED50) was 0.120 mg/kg for an
Emax of 11.15%. For clinical lameness score
(expressed as an absolute increase from the control
value), the ED50 was 0.265 mg/kg for an Emax of
9.16 units. The PK-PD analysis allowed calculation of
a median effective concentration of 130 ng/mL for
stride length and 195 ng/mL for lameness score. Use
of the Emax model predicted a maximal possible
increase in effect of 19.5% for stride length and
13.91 units for lameness score. For stride length and
lameness score, the Hill coefficient (slope) was
extremely high, which suggested a steep dose-effect
relationship.

Conclusions and Clinical Relevance—Results of
this study suggest that meloxicam is a potent anti-inflammatory
drug in horses. A dosage of 0.6 mg/kg/d
would be appropriate for use in a clinical study. (Am J Vet Res 2004;65:1533–1541)
Comparison of hepatic in vitro metabolism of the pyrrolizidine alkaloid senecionine in sheep and cattle
Authors: Duringer Jennifer M. , Buhler Donald R. , Craig A. Morrie 
Published: December 2005

AbstractObjective—To compare hepatic metabolism of pyrrolizidine alkaloids (PAs) between sheep and cattle and elucidate the protective mechanism of sheep.Sample Population—Liver microsomes and cytosol from 8 sheep and 8 cattle.Procedure—The PA senecionine, senecionineN-oxide (nontoxic metabolite) and 6,7-dihydro-7-hydroxy- 1-hydroxymethyl-5H-pyrrolizine (DHP; toxic metabolite) were measured in microsomal incubations. The kcat(turnover number) was determined for DHP and N-oxide formation. Chemical and immunochemical inhibitors were used to assess the role of cytochrome P450s, flavin-containing monooxygenases (FMOs), and carboxylesterases in senecionine metabolism. The CYP3A, CYP2B, and FMO concentrations and activities were determined, in addition to the role of glutathione (GSH) in senecionine metabolism.Results—DHP concentration did not differ between species. Sheep formed moreN-oxide, had higherN-oxide kcat, and metabolized senecionine faster than cattle. The P450 concentrations and isoforms had a large influence on DHP formation, whereas FMOs had a large influence onN-oxide formation. In cattle, CYP3A played a larger role in DHP formation than in sheep. FMO activity was greater in sheep than in cattle. Addition of GSH to in vitro microsomal incubations decreased DHP formation; addition of cytosol decreasedN-oxide formation.Conclusions and Clinical Relevance—Hepatic metabolism differences alone do not account for the variation in susceptibility seen between these species. Rather, increased ruminal metabolism in sheep appears to be an important protective mechanism, with hepatic enzymes providing a secondary means to degrade any PAs that are absorbed from the rumen. (Am J Vet Res2004;65:1563–1572)
Assessment of lipid peroxidation and serum vitamin E concentration in dogs with immune-mediated hemolytic anemia
Authors: Pesillo S. Anna , Freeman Lisa M. , Rush John E. 
Published: December 2005

AbstractObjective—To determine plasma malondialdehyde (MDA) and serum vitamin E concentrations in dogs with immune-mediated hemolytic anemia (IMHA) and healthy control dogs.Sample Population—Serum and plasma samples from 36 dogs with IMHA and 40 healthy control dogs.Procedure—Blood samples were collected from all study dogs. Plasma MDA concentrations were measured by use of a commercial colorimetric assay, and serum vitamin E concentrations (α-, γ-, and δ-tocopherol concentrations) were measured via high-performance liquid chromatography.Results—Plasma MDA concentrations were significantly higher in the dogs with IMHA than in the control dogs. Compared with control dogs, serum α-, γ-, and δ-tocopherol concentrations were significantly lower in the IMHA-affected dogs.Conclusions and Clinical Relevance—Results indicated a state of oxidative stress and reduced antioxidant reserve in dogs with IMHA; this finding provides support for further investigation of the potential benefits of antioxidant treatment in dogs with this disease. (Am J Vet Res2004;65:1621–1624)
Serum concentrations of cortisol, sex hormones of adrenal origin, and adrenocortical steroid intermediates in healthy dogs following stimulation with two doses of cosyntropin
Authors: Frank Linda A. , Davis Jacqueline A. , Oliver Jack W. 
Published: December 2005

AbstractObjective—To compare the effects of 2 doses of cosyntropin (5 µg/kg vs 250 µg, IV) on serum concentrations of cortisol, sex hormones of adrenal origin, and adrenocortical steroid intermediates and determine the optimal sample collection time after adrenal stimulation with cosyntropin.Animals—10 healthy, privately owned, neutered dogs.Procedure—Dogs were randomly assigned to initially receive cosyntropin at 5 µg/kg or as a total dose of 250 µg, IV. Dogs received the alternate dose 1 to 2 weeks later. Serum was obtained from blood samples collected before (0 minutes) and 30, 60, 90, and 120 minutes after cosyntropin administration.Results—Maximum stimulation of cortisol, androstenedione, progesterone, and 17-hydroxyprogesterone production was achieved at 60 minutes following IV administration of cosyntropin at 5 µg/kg or as a total dose of 250 µg. Serum estradiol concentration did not increase in response to either cosyntropin dose. For all hormones, no significant difference in serum hormone concentrations was found among sample collection times of 0, 30, 60, and 90 minutes when comparing the 2 doses of cosyntropin.Conclusions and Clinical Relevance—Cosyntropin, when administered at 5 µg/kg, IV, effectively stimulated maximum production of cortisol, sex hormones of adrenal origin, and adrenocortical steroid intermediates at 1 hour after administration. (Am J Vet Res2004;65:1631–1633)
Observer variation in visual assessment of forelimb horseshoe characteristics on Thoroughbred racehorses
Authors: Gross Diane K. , Stover Susan M. , Hill Ashley E. , Gardner Ian A. 
Published: December 2005

AbstractObjective—To assess the accuracy and reliability of a visual method of evaluating horseshoe characteristics.Animals—1,199 Thoroughbred racehorses.Procedure—Characteristics of 1 forelimb horseshoe were visually assessed on horses immediately prior to racing by 5 field observers at 5 major racetracks in California. Characteristics evaluated included horseshoe type; toe grab height; and the presence of a rim, pad, and heel traction devices. Sensitivity and specificity for observer assessment of horseshoe characteristics were calculated by comparing observer assessments to a postmortem laboratory standard for horses that died within 48 hours of a race. Intraobserver agreement was assessed in a subset of horses by comparing horseshoe observations made before and after the horse's race. Interobserver agreement was evaluated by comparing horseshoe assessment among observers who examined the same subset of horses prior to racing on select days.Results—The sensitivity and specificity of this visual method of evaluating horseshoe characteristics were good and ranged from 0.75 to 1 and 0.67 to 1, respectively. Agreement beyond chance (weighted kappa values) between observers and the laboratory standard for toe grab height was fair (0.60 to 0.62). Intraobserver and interobserver agreements (kappa values) were high (0.86 to 0.99 and 0.71 to 1, respectively).Conclusions and Clinical Relevance—Visual observation of horseshoes can be a feasible and reproducible method for assessing horseshoe characteristics prospectively in a large cohort of horses under racing conditions. (Am J Vet Res2004;65:1674–1679)
Expression of the cyclooxygenase isoforms in the prodromal stage of black walnut-induced laminitis in horses
Authors: Waguespack R. Wayne , Cochran Anne , Belknap James K. 
Published: December 2005

AbstractObjective—To compare the levels of mRNA expression of cycooxygenase (COX)-1 and COX-2 in the digital laminae of normal horses and horses in the developmental stages of laminitis experimentally induced by administration of black walnut extract (BWE).Sample Population—Samples of mRNA extracted from the digital laminae of 5 control horses and 5 horses at the onset of leukopenia after administration of BWE.Procedure—Specimens of laminae were collected from anesthetized horses prior to euthanasia. Expression of COX-1 and COX-2 mRNA in laminae of control and affected horses was evaluated via realtime quantitative polymerase chain reaction techniques.Results—Expression of COX-2 mRNA was significantly increased in the BWE-treated group, compared with that in control horses. In contrast to COX-2 regulation, COX-1 mRNA expression was not significantly different between groups. Interestingly, despite consistent clinical signs such as leukopenia in all BWE-treated horses, distinct differences in COX-2 mRNA expression were detected among those 5 horses (compared with values for control horses, the increase in COX-2 mRNA expression ranged from no increase to a 30-fold increase).Conclusions and Clinical Relevance—Results indicated that there was a significant upregulation of COX-2 mRNA expression during the developmental stages of laminitis, with no significant change in expression of the COX-1 isoform. These data appear to provide support for aggressive use of nonsteroidal anti-inflammatory drugs in horses at risk for laminitis; further investigation into the clinical value of selective COX-2 inhibitors for treatment of laminitis in horses appears to be warranted. (Am J Vet Res2004;65:1724–1729)
Comparison of the use of regulatory assays and high-performance liquid chromatography for detection of residues of ceftiofur sodium metabolites in tissue specimens of culled dairy cattle
Authors: Payne Michael A. , Wetzlich Scott E. , Robb Edward J. , Brown Scott A. , Gardner Ian A. , Cullor James S. , Craigmill Arthur L. 
Published: December 2005

AbstractObjective—To compare the results of regulatory screening and confirmation assays with those of highperformance liquid chromatography (HPLC) in the detection of ceftiofur metabolites in the tissues of culled dairy cattle.Animals—17 lactating Holstein dairy cows.Procedure—Daily IM injections of ceftiofur sodium were administered at a dose of 2.2 mg of ceftiofur equivalents/kg (n = 6) or 1.0 mg of ceftiofur equivalents/kg (10) for 5 days. Following withdrawal times of 12 hours (high-dose ceftiofur) and either 5 or 10 days (low-dose ceftiofur), cows were slaughtered and liver, kidney, and diaphragmatic muscle specimens were harvested and analyzed by HPLC and standard regulatory methods that included the following assays: the swab test on premises, the fast antimicrobial screen test, the calf antibiotic and sulfa test, and the 7-plate bioassay confirmation test.Results—In all tissue specimens, residues of ceftiofur and desfuroylceftiofur-related metabolites, as measured by HPLC, were less than regulatory tolerance, as defined by the FDA. False-positive screening assay results were more likely for tissue specimens that had been frozen for shipment to a federal laboratory, compared with fresh tissue specimens that were assayed at the slaughter establishment (23% vs 3% false-positive results, respectively).Conclusions and Clinical Relevance—The observation that fresh tissues had negative results on screening assays, whereas subsets of the same tissue specimens had false-positive results on screening assays following freezing, suggests that freezing and thawing interferes with microbial inhibition-based regulatory screening assays. (Am J Vet Res2004;65:1730–1733)
Molecular epidemiologic features of Corynebacterium pseudotuberculosis isolated from horses
Authors: Foley Janet E. , Spier Sharon J. , Mihalyi Judy , Drazenovich Niki , Leutenegger Christian M. 
Published: December 2005

AbstractObjective—To characterize isolates ofCorynebacterium pseudotuberculosisfrom horses, cattle, and sheep in Colorado, Kentucky, Utah, and California in samples collected during perceived epidemics of infection (increased numbers of cases identified) in 2002 and 2003, and determine how closely isolates were related and their possible source.Sample Population—54 isolates ofC pseudotuberculosisfrom 49 horses, 4 cattle, and 1 sheep.Procedures—Random amplified polymorphic DNA (RAPD) polymerase chain reaction (PCR) assay, PCR assay for the gene encoding the phospholipase D (PLD) toxin, biochemical analyses, and tests for susceptibility to 17 antimicrobial drugs were performed.Results—All isolates reduced nitrate to nitrite, most yielded positive results for the PLD toxin gene, and all were susceptible to antimicrobial drugs. Ten genetic types were detected by use of RAPD PCR assay; types III to X were isolated from horses, cattle, or both in 1 or more states. Types III and IX were isolated from both horses and cattle. Types VII and VIII were isolated in only 1 state, but the number of isolates in these groups was small. In contrast, all other types were isolated in 2 or more states. All isolates from Utah were type III, but the other 3 states had isolates from more than 1 type.Conclusions and Clinical Relevance—These data are consistent with a clonally expanding epidemic of infection in Utah and an increase in number of infections caused by multiple strains ofC pseudotuberculosisnot derived from a single source in the other states. The increase in number of infections could be the result of reporting bias, environmental factors facilitating infection, or host factors such as greater herd susceptibility. (Am J Vet Res2004;65:1734–1737)
Effects of feeding meals with various soluble-carbohydrate content on muscle glycogen synthesis after exercise in horses
Authors: Lacombe Véronique A. , Hinchcliff Kenneth W. , Kohn Catherine W. , Devor Stephen T. , Taylor Lynn E. 
Published: December 2005

AbstractObjectives—To determine effects of feeding diets with various soluble-carbohydrate (CHO) content on rates of muscle glycogen synthesis after exercise in horses.Animals—7 fit horses.Procedures—In a 3-way crossover study, horses received each of 3 isocaloric diets (a high soluble CHO [HC] diet, a low soluble CHO [LC] diet, or a mixed soluble CHO [MC] diet). For each diet, horses were subjected to glycogen-depleting exercise, followed by feeding of the HC, LC, or MC diet at 8-hour intervals for 72 hours.Results—Feeding the HC diet resulted in a significantly higher glycemic response for 72 hours and significantly greater muscle glycogen concentration at 48 and 72 hours after exercise, compared with results after feeding the MC and LC diets. Muscle glycogen concentrations similar to baseline concentrations were detected in samples obtained 72 hours after exercise in horses when fed the HC diet. Rate of glycogen synthesis was significantly higher when horses were fed the HC diet, compared with values when horses were fed the MC and LC diets. Glycogen synthase activity was inversely related to glycogen content. Protein content of glucose transporter-4 was the lowest at 72 hours after exercise when horses were fed the HC diet.Conclusions and Clinical Relevance—Muscle glycogen synthesis was slower after glycogen-depleting exercise in horses, compared with synthesis in humans. Feeding HC meals after strenuous exercise hastened replenishment of muscle glycogen content, compared with results for feeding of LC and MC diets, by increasing availability of blood glucose to skeletal muscles. (Am J Vet Res2004;65:916–923)
Variation in free jumping technique within and among horses with little experience in show jumping
Authors: Santamaría Susana , Bobbert Maarten F. , Back Willem , Barneveld Ab , van Weeren P. René 
Published: December 2005

AbstractObjective—To quantify variation in the jumping technique within and among young horses with little jumping experience, establish relationships between kinetic and kinematic variables, and identify a limited set of variables characteristic for detecting differences in jumping performance among horses.Animals—Fifteen 4-year-old Dutch Warmblood horses.Procedure—The horses were raised under standardized conditions and trained in accordance with a fixed protocol for a short period. Subsequently, horses were analyzed kinematically during free jumping over a fence with a height of 1.05 m.Results—Within-horse variation in all variables that quantified jumping technique was smaller than variation among horses. However, some horses had less variation than others. Height of the center of gravity (CG) at the apex of the jump ranged from 1.80 to 2.01 m among horses; this variation could be explained by the variation in vertical velocity of the CG at takeoff (r, 0.78). Horses that had higher vertical velocity at takeoff left the ground and landed again farther from the fence, had shorter push-off phases for the forelimbs and hind limbs, and generated greater vertical acceleration of the CG primarily during the hind limb pushoff. However, all horses cleared the fence successfully, independent of jumping technique.Conclusions and Clinical Relevance—Each horse had its own jumping technique. Differences among techniques were characterized by variations in the vertical velocity of the CG at takeoff. It must be determined whether jumping performance later in life can be predicted from observing free jumps of young horses. (Am J Vet Res2004;65:938–944)
Evaluation of consistency of jumping technique in horses between the ages of 6 months and 4 years
Authors: Santamaría Susana , Bobbert Maarten F. , Back Willem , Barneveld Ab , van Weeren P. René 
Published: December 2005

AbstractObjective—To determine whether differences in jumping technique among horses are consistent at various ages.Animals—12 Dutch Warmblood horses.Procedure—Kinematics were recorded during free jumps of horses when they were 6 months old (ie, no jumping experience) and 4 years old (ie, the horses had started their training period to become show jumpers). Mean ± SD height of the horses was 1.40 ± 0.04 m at 6 months of age and 1.70 ± 0.05 m at 4 years of age.Results—Strong correlations were found between values from 6-month-old foals and 4-year-old horses for variables such as peak vertical acceleration generated by the hind limbs (r, 0.91), peak rate of change of effective energy generated by the hind limbs (r, 0.71), vertical velocity at takeoff (r, 0.65), vertical displacement of the center of gravity during the airborne phase (r, 0.81), and duration of the airborne phase (r, 0.70).Conclusions and Clinical Relevance—Although there are substantial anatomic and behavioral changes during the growing period, certain characteristics of jumping technique observed in naïve 4-year-olds are already detectable when those horses are foals. (Am J Vet Res2004;65:945–950)