Search Results

Abstract

Objective—To estimate prevalence of and identify factors associated with anhidrosis in horses in Florida.

Design—Cross-sectional study and case-control study.

Animals—4,620 horses on 500 farms.

Procedures—A questionnaire was structured and mailed to farm owners or managers to obtain information related to diagnosis of anhidrosis in horses and exposure factors associated with this condition. The frequency of investigated farm- and animal-level factors was compared between farms and horses affected and not affected with anhidrosis, respectively.

Results—The prevalence of anhidrosis was 11% at the farm level and 2% at the animal level. The odds of anhidrosis were 2.13 and 4.40 times as high in farms located in central and southern Florida, respectively, compared with odds for farms in northern Florida. The odds of anhidrosis were 5.26 and 15.40 times as high in show and riding instruction operations, respectively, compared with odds for ranch operations. At the animal level, breed (Thoroughbreds and warmblood horses), foaling place (western or midwestern region of the United States), and family history of anhidrosis were significantly associated with anhidrosis.

Conclusions and Clinical Relevance—This study provides new information on the prevalence of and factors for anhidrosis in horses in Florida. Horses with a family history of anhidrosis should be examined by a veterinarian for diagnosis of this condition before they are exposed to exercise in a hot and humid climate.

Abstract

Objective—To assess awareness, perceived relevance, and acceptance of surveillance and infection control practices at a large animal referral hospital among referring veterinarians and clients who sent horses to the facility for veterinary care.

Design—Survey.

Sample—57 referring veterinarians and 594 clients.

Procedures—A 15-question survey targeting Salmonella enterica as an important pathogen of interest in horses was sent to clients who sent ≥ 1 horse to the University of Florida Large Animal Hospital for veterinary care during July 1, 2007, through July 1, 2011, and to veterinarians who had referred horses to the same hospital prior to July 1, 2011. Responses were summarized with descriptive statistics. The χ² test and the Wilcoxon rank sum test were used to examine associations among variables of interest.

Results—Survey response rates were low (57/467 [12%] for veterinarians and 594/3,095 [19%] for clients). Significantly more (35/56 [63%]) veterinarians than clients (227/585 [39%]) were aware that the hospital operates a surveillance and infection control program. Most veterinarians (56/57 [98%]) and clients (554/574 [97%]) indicated that sampling and testing of horses to detect Salmonella shedding in feces at admission and during hospitalization was justified. In addition, on a scale of 1 (not important) to 10 (very important), veterinarians and clients indicated it was very important (median score, 10 [interquartile range, 8 to 10] for both groups) that a referral hospital operates a surveillance and infection control program.

Conclusions and Clinical Relevance—Survey results indicated that awareness of hospital surveillance and infection control practices was higher among veterinarians than clients, and these practices were considered relevant and well-accepted among participant veterinarians and clients.

Abstract

Objective—To evaluate horseshoe characteristics and high-speed exercise history as risk factors for catastrophic musculoskeletal injury in Thoroughbred racehorses.

Animals—377 horses (37,529 race starts).

Procedure—Shoe characteristics included material, toe grab height, heel traction device, pads, and rim shoes. Racing variables were obtained from a computerized database. Forty-three horses that had a musculoskeletal injury and then failed to race or train for 6 months (cases) and 334 noninjured horses from the same race in which a horse was injured (controls) were compared regarding risk factors.

Results—Overall, 98% of race starts were associated with aluminum shoes, 85% with toe grabs, 32% with pads, and 12% with rims on forelimb horseshoes. Among 43 horses with musculoskeletal injury, sex (geldings), an extended interval since last race, and reduced exercise during the 30 or 60 days preceding injury were risk factors for catastrophic injury. Odds of injury in racehorses with toe grabs on front shoes were 1.5 times the odds of injury in horses without toe grabs, but this association was not significant (95% confidence interval, 0.5 to 4.1).

Conclusions and Clinical Relevance—Results suggest that horses that return to racing after an extended period of reduced exercise are at high risk of catastrophic musculoskeletal injury. Results regarding the use of toe grabs as a possible risk factor for catastrophic injury were inconclusive because the probability of declaring (in error) that use of toe grabs was associated with an increased risk of musculoskeletal injury (eg, odds ratio > 1.0) was 38%. (Am J Vet Res 2005;66:1314–1320)

Abstract

Objective—To determine the effects of yearling sale purchase price, exercise history, lameness, and athletic performance (speed) on purchase price of 2-year-old in-training Thoroughbreds and to compare the distance exercised within 60 days prior to 2-year-old in-training sales between horses with high yearling sale purchase prices versus those with low yearling sale purchase prices and between horses with lameness during training and those without lameness during training.

Design—Prospective study.

Animals—51 Thoroughbreds.

Procedures—Thoroughbreds purchased at a yearling sale were trained prior to resale at 2-year-old in-training sales. Amount of exercise and lameness status during training and speed of horses at 2-year-old in-training sales were determined. Data were analyzed via the Wilcoxon rank sum test and ANOVA.

Results—Median purchase price of horses at 2-year-old in-training sales was $37,000. The 2-year-old in-training sale purchase price was associated with yearling sale purchase price and distance galloped within 60 days prior to and speed recorded at 2-year-old in-training sales.

Conclusions and Clinical Relevance—Horses with high yearling sale purchase prices typically had high 2-year-old in-training sale purchase prices, had low distances galloped within 60 days prior to 2-year-old in-training sales, and were classified as fast at 2-year-old in-training sales. Lameness alone was not associated with 2-year-old in-training sales purchase price. However, lameness was associated with a low distance galloped before 2-year-old in-training sales, particularly for horses with a high yearling sale purchase price; this finding suggested that yearling sale purchase price can affect training management decisions for horses with lameness.

Abstract

Objective—To determine the effects of various presale radiographic findings for Thoroughbreds sold at a yearling sale on 2-year-old racing performance of those horses.

Animals—397 Thoroughbreds.

Design—Cohort study.

Procedures—Thoroughbreds offered for sale at a Thoroughbred sales facility in Kentucky were selected via a randomization procedure. Effects of various presale radiographic findings on the following measures of 2-year-old racing performance were determined: having started a race and having placed (ie, finished in first, second, or third place) in a race at least once, total amount of money earned, and amount of money earned per start.

Results—Of the 397 horses, 192 (48%) started in at least 1 race during the 2-year-old racing year. The odds of failure to start a race as a 2-year-old were 1.78 times as great for horses with forelimb proximal sesamoid bone osteophytes or enthesophytes as for horses without this finding (95% confidence interval, 1.01 to 3.16). The odds of failure to start a race as a 2-year-old were 2.02 times as great for horses with hind limb proximal phalanx osteochondral fragments as for horses without this finding (95% confidence interval, 0.95 to 4.31), although this result was not significant. Radiographic findings did not have an effect on total amount of money earned, amount of money earned per start, or whether horses placed in a race.

Conclusions and Clinical Relevance—Presale radiographic detection of forelimb proximal sesamoid bone osteophytes or enthesophytes or hind limb proximal phalanx osteochondral fragments in yearlings were associated with failure to start a race during the 2-year-old racing year in study horses.

Abstract

Objective—To assess the efficacy of prophylactic hoof health examination and trimming during midlactation at reducing the incidence of lameness during late lactation in dairy cows.

Design—Randomized field trial.

Animals—333 Holstein cows.

Procedures—Cows without apparent lameness were randomly allocated into 1 of 2 groups approximately 204 days after calving. Cows allocated to the treatment group (n = 161) were examined on a tilt table for diagnosis and underwent hoof-trimming procedures, if needed, for treatment of hoof disorders or lesions. Cows in the control group (n = 172) were not examined. Cows were assigned a locomotion score weekly for 28 weeks after allocation to a group. The number of cows classified as lame during late lactation (approx 205 to 400 days after calving) was compared between groups to assess the efficacy of prophylactic examination and trimming.

Results—Incidence of lameness during late lactation was 24% in cows in the control group and 18% in cows in the treatment group.

Conclusions and Clinical Relevance—The 25% decrease in number of new cases of lameness in cows undergoing prophylactic hoof health examination and trimming during midlactation may be relevant for the well-being of dairy cows and should not represent a major economic burden to producers.

Abstract

Objective—To characterize lameness during training and compare exercise variables and financial returns among yearling Thoroughbreds that were bought for the purpose of resale for profit.

Animals—40 yearling Thoroughbreds.

Design—Prospective study.

Procedures—Horses purchased at yearling sales (summer 2004) were trained prior to resale at 2-year-olds in training sales (spring 2005). Horses were monitored daily for diagnosis and treatment of lameness during training. Selected variables, including sex, age, purchase price, lameness, distance (No. of furlongs) galloped during training, and financial returns, were compared among horses that had performance speeds (assessed at 2-year-olds in training sales) classified as fast, average, or slow.

Results—37 of 40 horses became lame during training, most commonly because of joint injury. Eighteen of the lame horses had hind limb injuries only; 5 horses had injuries in forelimbs and hind limbs. The frequency of new cases of lameness increased as the date of the 2-year-olds in training sales approached. At the sales, 4, 21, and 15 horses were classified as fast, average, or slow, respectively; median financial return was slightly (but significantly) different among horses classified as fast ($14,000), average ($0), or slow (–$8,000).

Conclusions and Clinical Relevance—Incidence of lameness during training in yearling horses purchased for the purpose of resale for profit was high. Lameness more commonly affected hind limbs than forelimbs and was attributable to joint injury in most horses. Financial returns differed between horses classified as fast and average or slow at the 2-year-olds in training sales.

Abstract

Objective—To compare calving-to-conception intervals among cows classified as nonlame, moderately lame, or lame during the prebreeding postpartum period and to examine the relationship between severity of lameness and time to conception in cows that were classified as lame.

Design—Longitudinal study.

Animals—499 Holstein cows.

Procedure—Cows in the prebreeding postpartum period were classified as nonlame, moderately lame, or lame by use of a 6-point locomotion scoring system. Time to conception (days) was compared among cows. A low, medium, or high cumulative locomotion score was assigned to lame cows, and time to conception among those cows was compared. Cows classified as lame were examined on a tilt table for diagnosis and treatment of lameness.

Results—154 (31%), 214 (43%), and 131 (26%) cows were classified as nonlame, moderately lame, and lame, respectively. Most cows classified as lame had laminitis (54%) or disorders of the claw (33%). Median time to conception was 36 to 50 days longer in lame cows than in nonlame cows. Among lame cows, the median time to conception was 66 days longer in cows with high cumulative locomotion scores than in cows with low scores.

Conclusion and Clinical Relevance—Nonlame cows became pregnant more quickly than lame cows. Lame cows with low cumulative locomotion scores during the prebreeding postpartum period became pregnant sooner than lame cows with high scores. Early diagnosis and intervention may mitigate the effects of lameness and improve reproductive performance in lame dairy cows. (J Am Vet Med Assoc 2005;227:1284–1291)

Abstract

Objective—To compare milk yield among cows classified as nonlame, moderately lame, and lame and to examine the relationship between severity of lameness and milk yield in cows classified as lame during the first 100 days after parturition.

Design—Longitudinal study.

Animals—465 Holstein cows.

Procedure—Cows were examined weekly during the first 100 days after parturition and assigned a lameness score by use of a 6-point locomotion scoring system (ie, 0 to 5). Milk yield was compared among cows classified as nonlame, moderately lame, and lame. Among cows classified as lame (locomotion score ≥ 4), milk yield was compared for cows with low, medium, and high cumulative locomotion scores. Cows classified as lame were further examined on a tilt table for diagnosis and treatment of lameness.

Results—84 (18%), 212 (46%), and 169 (36%) cows were classified as nonlame, moderately lame, and lame, respectively. Among cows in their second or later lactations, milk yield in lame cows was significantly lower than that in moderately lame and nonlame cows. In addition, among cows classified as lame, milk yield was significantly lower in cows with high locomotion scores during the first 100 days after parturition, compared with cows with low scores. Most (58%) cows classified as lame had laminitis.

Conclusions and Clinical Relevance—Results indicate a linear relationship between increasing degree of lameness and decreasing milk yield among cows in their second or later lactations. The locomotion scoring system used in this study may be a useful management tool that veterinarians and dairy farmers could adopt for early detection of lameness in dairy cows. (J Am Vet Med Assoc 2005;227:1292–1296)

Abstract

Objective—To determine whether passive transfer of IgG in neonatal kittens affects plasma opsonic capacity and neutrophil phagocytic and oxidative burst responses to bacteria in vitro.

Animals—22 kittens from 6 specific pathogen-free queens.

Procedure—Kittens were randomized at birth into the following treatment groups: colostrum-fed, colostrum-deprived, or colostrum-deprived supplemented with feline or equine IgG. Blood samples were collected at intervals from birth to 56 days of age. Plasma IgG concentrations were determined by radial immunodiffusion assay. Neutrophil function was assessed by a flow cytometry assay providing simultaneous measurement of bacteria-induced phagocytosis and oxidative burst. The opsonic capacity of kitten plasma was determined in an opsonophagocytosis assay with bacteria incubated in untreated or heat-inactivated plasma.

Results—Among treatment groups, there were no significant differences in neutrophil phagocytic and oxidative burst responses to bacteria or opsonic capacity of plasma. In all samples of plasma, inactivation of complement and other heat-labile opsonins significantly reduced the opsonic capacity. Plasma IgG concentrations in kittens did not correlate with neutrophil function or plasma opsonic capacity before or after inactivation of complement.

Conclusions and Clinical Relevance—The plasma opsonic capacity and neutrophil phagocytic and oxidative burst responses in vitro of kittens receiving passive transfer of IgG via colostrum intake or IgG supplementation and those deprived of colostrum were similar. The alternate complement pathway or other heat-labile opsonins may be more important than IgG in bacterial opsonization and phagocytosis. ( Am J Vet Res 2003;64:538–543)