Search Results

You are looking at 1 - 10 of 36 items for

  • Author or Editor: Jorge Hernandez x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract

OBJECTIVE

This study aimed to compare the effects of low-dose subarachnoid injections of 2% lidocaine (LIDO) and 0.5% bupivacaine (BUPI) in goats.

ANIMALS

6 healthy, privately owned female goats.

METHODS

In this randomized blind crossover clinical trial, each goat received 0.05 mL/kg−1 of LIDO, BUPI, or sterile saline solution into the lumbosacral subarachnoid space, with a seven-day washout. Cardiorespiratory variables, rectal temperature, and somatosensory (pinprick) and motor (ataxia) functions were recorded at baseline (time 0) and 2, 5, 10, 15, and 30 minutes after injection, then every 20 minutes until the goat was standing and able to walk. Time to regain somatosensory and motor functions was compared between treatments using Kaplan-Meier survival curves and the Cox proportional hazards model. Linear mixed-effects models were used to compare cardiorespiratory variables between treatments and over time. A P value ≤ .05 was considered significant.

RESULTS

Somatosensory recovery was longer with BUPI, though not statistically significant. The median time to stand was 50 (50, 67) minutes after LIDO injection and 104 (101, 156) minutes after BUPI injection (P = .031). The median time to walk was 72 (54, 85) minutes after LIDO versus 225 (220, 245) minutes after BUPI injection (P = .031). Cardiovascular and respiratory variables showed no significant differences between treatments.

CLINICAL RELEVANCE

Despite prolonged ataxia with BUPI, pinprick sensation recovery did not differ. At reduced doses, both LIDO and BUPI are deemed acceptable for short procedures of the flank, pelvic limb, or tail in healthy goats.

Open access
in American Journal of Veterinary Research

Summary

An elisa was compared with the plaque-reduction serum neutralization (prsn) test, for detection of vesicular stomatitis virus (vsv) antibodies in cattle in a vesicular stomatitis enzootic region of Mexico. A total of 325 bovine serum samples were screened for vsv antibodies. The prsn test was performed, using Vero cells. The elisa contained gradient-purified vsv Indiana (Lab strain) and vsv New Jersey (Hazelhurst) as the antigens. Regression analysis and weighted kappa statistic were used to estimate measures of agreement between the 2 assays for detection of vsv antibodies. The elisa method proved useful for sero-diagnosis of vesicular stomatitis The elisa and prsn test results were highly correlated for detection of vsv antibodies.

Free access
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)

Full access
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

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)

Full access
in American Journal of Veterinary Research

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)

Full access
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)

Full access
in American Journal of Veterinary Research

Objective

To implement a disease monitoring system in federal, municipal, and private abattoirs in Baja California, Mexico and to estimate annual prevalence of tuberculosis (TB) in beef and dairy cattle slaughtered and inspected in 1995 and 1996.

Design

Epidemiologic survey.

Animals

About 200,000 cattle (95% beef, 5% dairy).

Procedures

Lymph node and tissue specimens with lesions suggestive of TB were fixed in neutral-buffered 10% formalin and embedded in paraffin. Sections were stained with H&E and Ziehl-Neelsen and examined for typical tuberculous lesions and acid-fast bacilli. Annual prevalence and 95% confidence intervals were estimated.

Results

Prevalence of TB in all slaughtered cattle was 0.12 and 0.46% in 1995 and 1996, respectively (beef cattle, 0.02 and 0.05%, respectively; dairy cattle, 2.0 and 8.3%, respectively). Tuberculosis cases/1,000 slaughtered cattle were linearly associated with monthly volumes of tissue submissions.

Clinical Implications

It is critical to quantify the monitoring activity at abattoirs to better estimate the prevalence of TB in slaughtered cattle. Annual prevalence of TB was significantly greater in dairy cattle than in beef cattle. Veterinarians and cattle producers in this region are encouraged to develop and work on herd plans aimed at controlling and eradicating TB. (J Am Vet Med Assoc 1997;211:709–711)

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine association between exposure to Neospora caninum and milk production in dairy cows.

Design—Prospective observational study.

Animals—565 Holstein cows.

Procedure—Cows were classified as seropositive or seronegative to N caninum within 7 days after calving by use of a kinetic ELISA. Milk production was compared between seropositive and seronegative cows.

Results—On the basis of 305-day mature equivalent milk production data, seropositive cows produced less milk (2.8 lb/cow per day) than did seronegative cows. In addition, analysis of results throughout the first 300 days of lactation revealed that after adjusting for effects of lactation number, calving season, clinical mastitis, and lameness, milk weight of seropositive cows was 2.5 lb/cow per day less than that of seronegative cows.

Conclusions and Clinical Relevance—Exposure to N caninum was associated with a 3 to 4% decrease in milk production. A decrease in milk production of 800 lb/cow for a typical 305-day lactation represents a loss of $128/cow. (J Am Vet Med Assoc 2001; 219:632–635)

Full access
in Journal of the American Veterinary Medical Association

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.

Full access
in Journal of the American Veterinary Medical Association