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Abstract

Objective—To compare financial returns between pinhooked yearling horses (ie, bought and trained for approximately 5 months with the goal of selling the horse at "2-year-olds in training" sales) that had mild or severe training failure and horses that had planned versus nonplanned training failure.

Animals—40 Thoroughbred pinhooked yearling horses.

Procedure—During the period from September 1998 through and April 1999, 20 horses had mild training failure (1 to 11 days lost), and 20 horses had severe training failure (13 to 108 days lost). Horses were assigned to these 2 groups on the basis of frequency distribution (median) of days lost during training. Horses were also categorized on the basis of type of training failure (planned vs nonplanned training failure). The outcome of primary interest was financial return. Median financial returns were compared among groups by use of the Mann-Whitney U test.

Results—Median financial returns for horses that had severe training failure ($1,000) were significantly different, compared with horses that had mild training failure ($24,000). Analysis of results also indicated that median returns were significantly different among horses that had planned training failure (−$2,000; eg, horses with radiographic abnormalities detected during routine prepurchase examinations that required surgical treatment, resulting in days lost during training), compared with horses that did not ($10,000).

Conclusions and Clinical Relevance—Training failure has an economic impact on revenues in pinhooked yearling horses. Lameness, planned training failure, respiratory disease, and ringworm were common and important causes of training failure. (Am J Vet Res 2001;62:1418–1422)

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in American Journal of Veterinary Research

Abstract

Objective—To compare 3 types of noxious stimuli applied to various anatomic areas of anesthetized dogs and rabbits for determination of the minimum alveolar concentration (MAC).

Animals—10 dogs and 10 rabbits.

Procedure—Dogs were anesthetized with isoflurane and halothane in a randomized order. Rabbits were anesthetized with isoflurane. The MAC was determined by skin incision on the lateral aspect of the chest; clamping of the tail, paw of the forelimb, and paw of the hind limb; and application of electrical current to the oral mucosa (dogs only), forelimb, and hind limb. The MAC was the end-tidal concentration midway between the value permitting and preventing purposeful movement in response to noxious stimuli.

Results—In dogs, mean ± SEM MAC for isoflurane was 1.27 ± 0.05% for clamping stimuli, 1.36 ± 0.04% for oral electrical stimulation, 1.35 ± 0.04% for electrical stimulation to the limbs, and 1.01 ± 0.07% for surgical incision. The MAC for halothane was 0.97 ± 0.03% for tail clamping, 0.96 ± 0.03% for clamping of the limbs, 1.04 ± 0.03% for electrical stimulation, and 0.75 ± 0.06% for surgical incision. In rabbits, MAC for isoflurane was 2.08 ± 0.02% for clamping stimuli, 2.04 ± 0.02% for electrical stimulation, and 0.90 ± 0.02% for surgical incision. The MAC for surgical incision was significantly lower than values for the other methods in both species.

Conclusions and Clinical Relevance—Use of electrical current and clamping techniques resulted in similar MAC values. Surgical incision underestimated MAC values in dogs and rabbits. (Am J Vet Res 2003;64:957–962)

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in American Journal of Veterinary Research

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)

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in American Journal of Veterinary Research

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)

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in American Journal of Veterinary Research

Abstract

OBJECTIVE To compare pursestring, Witzel (seromuscular inversion), and seromuscular incision jejunostomy tube placement techniques in vitro.

SAMPLE Jejunal specimens from 10 dogs.

PROCEDURES Jejunal segments (50 cm) were harvested immediately prior to euthanasia from 10 mixed-breed dogs Specimens were harvested with the orad and aborad ends clamped and stored in saline (0.9% NaCl) solution–soaked towels during instrumentation. Three jejunostomy tubes were placed via 3 techniques (pursestring, Witzel, and seromuscular incision), and 2 double lumen central venous catheters were placed at each intestinal end for luminal filling and leak testing. Intestinal luminal area was measured ultrasonographically with specimens suspended in a warm undyed saline solution bath with the intestinal lumen filled with dyed saline solution (intraluminal pressure, 6 mm Hg). Leak testing was performed by means of infusion of dyed saline solution (4 mL/min) until each jejunostomy site failed. Intestinal luminal area and leakage pressure were compared between the 3 tube placement techniques.

RESULTS The Witzel and seromuscular incision techniques decreased the intestinal luminal area measured at the tube insertion site, albeit nonsignificantly. For the seromuscular incision technique, a significant decrease in intestinal luminal area at the intraluminal site of measurement was found. For 2/30 specimens (1/10 pursestring and 1/10 seromuscular incision), failure occurred at pressures within the range of previously reported peak peristaltic pressure for dogs. Failure occurred at supraphysiologic peristaltic pressures for the remaining 28 specimens, including all 10 specimens for the Witzel technique.

CONCLUSIONS AND CLINICAL RELEVANCE In this in vitro study, all specimens for the Witzel technique withstood physiologic peristaltic pressures during leak testing. Both tunneling techniques (Witzel and seromuscular incision) created a decrease in intestinal luminal area. Further investigation, including in vivo testing, is indicated to evaluate the clinical relevance of these findings.

Full access
in American Journal of Veterinary Research