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Objective

To assess veterinary extension in the United States as perceived by veterinary extension personnel.

Design

Cross-sectional survey.

Sample Population

Extension veterinarians in the United States.

Procedure

2 surveys were designed and mailed to extension veterinarians listed by the USDA and the American Association of Extension Veterinarians.

Results

34 states had ≥ 1 extension veterinarian. The majority (> 60%) of extension veterinarians did not commit time to resident education and were not involved in research activities. Paradoxically, 23% of responding extension veterinarians did not report extension work. Programs for food animal producers, horse owners, and companion animal owners were provided by 100, 63, and 37% of states, respectively. Continuing education (CE) programs were provided for food animal veterinarians, equine veterinarians, and companion animal veterinarians by 96, 63, and 52% of states, respectively. Challenges facing veterinary extension included limited recognition of veterinary extension activities by universities, lack of university personnel to support CE programs, and decreased support for companion animal extension programs.

Conclusions and Clinical Relevance

Extension veterinarians need to identify and clearly articulate the mission of veterinary extension, develop more collaborative programs across regions, and continue to serve as catalysts to bring diverse constituents together. Extension veterinarians must distinguish their mission not solely as information transfer, which can be accomplished in a variety of ways outside of extension, but as a coherent and consistent program of education and policy developed on a national level and distributed locally. (J Am Vet Med Assoc 1999;215:1439–1443)

Free access
in Journal of the American Veterinary Medical Association

Objective

To examine the study design of, and the practice of causal inference in, investigations of bacterial foodborne disease outbreaks occurring in the United States and to summarize agents and vehicles identified.

Design

Retrospective study.

Procedure

An online medical reference database was searched for reports of bacterial foodborne disease outbreak investigations published between 1986 and 1995. Reports were retrieved and reviewed for use of 9 causal criteria in investigations Information on etiologic agents, vehicles, seasonality, and primary study design from each outbreak was also retrieved.

Results

82 reports were retrieved and reviewed Coherence, consistency, temporality, and strength of association were the causal criteria most commonly used in foodborne disease outbreak investigations. Coherence was used in all investigations. The number of criteria used ranged from 3 to 7. Meat (n = 20) and eggs (12) were the most commonly implicated vehicles. Salmonella sp and Escherichia coli 0157:H7 accounted for 55% of agents reportedly isolated. Cohort and case-control methods were the most common study designs.

Clinical Relevance

Patterns were found in the use of causal criteria in foodborne disease outbreak investigations. These criteria can provide veterinarians and other public health practitioners with a means to effectively conceptualize, communicate, and summarize causal conclusions. The 4 most commonly used criteria may represent core criteria that investigators consider most useful in explaining foodborne disease outbreaks. (J Am Vet Med Assoc 1998:212:1874–1881)

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the efficacy of a modified-live virus vaccine containing bovine herpes virus 1 (BHV-1), bovine respiratory syncytial virus (BRSV), parainfluenza virus 3, and bovine viral diarrhea virus (BVDV) types 1 and 2 to induce neutralizing antibodies and cell-mediated immunity in naïve cattle and protect against BHV-1 challenge.

Animals—17 calves.

Procedures—8 calves were mock-vaccinated with saline (0.9% NaCl) solution (control calves), and 9 calves were vaccinated at 15 to 16 weeks of age. All calves were challenged with BHV-1 25 weeks after vaccination. Neutralizing antibodies and T-cell responsiveness were tested on the day of vaccination and periodically after vaccination and BHV-1 challenge. Specific T-cell responses were evaluated by comparing CD25 upregulation and intracellular interferon-γ expression by 5-color flow cytometry. Titration of BHV-1 in nasal secretions was performed daily after challenge.

Results—Vaccinated calves seroconverted by week 4 after vaccination. Antigen-specific cell-mediated immune responses, by CD25 expression index, were significantly higher in vaccinated calves than control calves. Compared with control calves, antigen-specific interferon-γ expression was significantly higher in calves during weeks 4 to 8 after vaccination, declining by week 24. After BHV-1 challenge, both neutralizing antibodies and T-cell responses of vaccinated calves had anamnestic responses to BHV-1. Vaccinated calves shed virus in nasal secretions at significantly lower titers for a shorter period and had significantly lower rectal temperatures than control calves.

Conclusion and Clinical Relevance—A single dose of vaccine effectively induced humoral and cellular immune responses against BHV-1, BRSV, and BVDV types 1 and 2 and protected calves after BHV-1 challenge for 6 months after vaccination.

Full access
in American Journal of Veterinary Research

SUMMARY

Ten 8- to 10-month-old cattle were each inoculated intramuscularly, subcutaneously, intracerebrally, and orally with the scrapie agent to determine whether cattle are susceptible to it. Two inocula, both 10% homogenates of cerebrum, were used. One inoculum was from a sheep used for the second experimental ovine passage of the agent from 4 naturally affected Suffolk sheep. The other inoculum was from a goat used for the first experimental caprine passage of the agent from 2 naturally affected dairy goats living with the Suffolk sheep, the source of their infection. Between 27 and 48 months after inoculation, neurologic disease was observed in 1 of 5 cattle given the sheep brain homogenate and in 2 of 5 given the goat brain homogenate. In all 3 affected cattle, the disease was expressed clinically as increasing difficulty in rising from recumbency, stilted gait of the pelvic limbs, disorientation, and terminal recumbency during a 6- to 10-week course. Neurohistologic changes, though consistent with those of scrapie, were slight and subtle: moderate astrocytosis with sparse rod cells, some neuronal degeneration, a few vacuolated neurons, and scant spongiform change. Clinically and neurohistologically, the experimentally induced disease differed from bovine spongiform encephalopathy. The differences emphasize that such infections in cattle induce diverse responses, presumably depending largely on the strain of the agent. Pathologists should keep this variability in mind when looking for microscopic evidence of a scrapie-like encephalopathy in cattle.

Free access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

Compare 3 methods of nucleus pulposus (NP) volume measurement using the rabbit lumbar spines as a preclinical model to determine the effectiveness of prophylactic intervertebral disk fenestration in dogs.

ANIMALS

Twelve 9-month-old, skeletally mature female entire New Zealand White rabbits weighing between 3.5 to 4.5 kg.

METHODS

NP volume measurements of dissected rabbit lumber spines between L1 and L6 were made and compared using gross measurements, reconstructed MRI images, and water volumetry based on Archimedes’ principle. Water volumetry was used as the true gold standard volume measurement in this study.

RESULTS

The true volume (mean ± SD) of the nucleus pulposus NP as measured by water volumetry increased caudally from L1/L2 (16.26 ± 3.32 mm3) to L5/L6 (22.73 ± 6.09 mm3). Volume estimates made by MRI were significantly higher than those made using water volumetry at all sites (L1/L2 [P = .044], L2/L3 [P = .012], L3/L4 [P = .015], L4/L5 [P < .001], and L5/L6 [P < .001]). Gross measurements also significantly overestimated volume when compared to water volumetry at all sites; L1/L2 (P = .021), L2/L3 (P = .025), L3/L4 (P = .001), L4/L5 (P < .001), and L5/L6 (P < .001). MRI and gross volume estimates were significantly different at L4/L5 (P = .035) and L5/L6 (P = .030).

CLINICAL RELEVANCE

The findings of this preclinical model might be relevant to veterinary surgeons who perform prophylactic fenestration for which there is no reliable method to determine the amount of NP to be removed. Preclinical ex vivo and in vivo fenestration studies with pre- and postoperative NP volume assessment are required.

Open access
in American Journal of Veterinary Research

Abstract

Objective—To generate data on the effects of firocoxib administration to horses with osteoarthritis.

Animals—Client-owned horses with signs of lameness and joint pain associated with osteoarthritis.

Procedures—Firocoxib was administered as an oral paste (0.1 mg/kg, q 24 h) for 14 days. Assessments were performed on day 0 (baseline) and days 7 and 14.

Results—390 of 429 horses from 80 sites in 25 states met the criteria for analysis. Quarter Horse and Thoroughbred were the 2 most commonly represented breeds, comprising half of the study population. Signs of musculoskeletal pain or lameness attributed to osteoarthritis were diagnosed in a single joint in 197 (197/390 [50.5%]) horses and in multiple joints in 193 (193/390 [49.5%]) horses. In those with involvement of a single joint, the tarsus was the most frequently affected joint (79/197 [40.1 %]). Among the 390 horses with complete lameness data, improvement was reported in approximately 80% by day 14. Investigators rated 307 (78.7%) horses as improved, whereas owners or handlers rated 316 (81.0%) horses as improved at the termination of the study. Horses treated with firocoxib paste had significant improvement in lameness scores from baseline values. Improvement was most rapid within the first 7 days after starting treatment and continued, albeit at a slower rate, through treatment day 14.

Conclusions and Clinical Relevance—Firocoxib significantly improved lameness scores throughout the 14-day period with few adverse effects. Firocoxib can be a safe cyclooxygenase-2–specific NSAID for the treatment of musculoskeletal pain and lameness associated with osteoarthritis.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine the accuracy of 3-D and 2-D ultrasonography for quantification of tumor volume in dogs with transitional cell carcinoma (TCC) of the urinary bladder.

Animals—10 dogs with biopsy-confirmed TCC.

Procedures—The urinary bladder of each dog was distended with saline (0.9% NaCl) solution (5.0 mL/kg), and masses were measured via 3-D and 2-D ultrasonography. Masses were also measured via 3-D ultrasonography after bladders were distended with 2.5 and 1.0 mL of saline solution/kg. Subsequently, the bladder was deflated and distended with CO2 (5.0 mL/kg); CT was performed after IV contrast medium administration. Tumor volumes were calculated via 3-D ultrasonography, 2-D ultrasonography, and CT (reference method) and compared via ANOVA, Deming regression, and Bland-Altman plots. Repeated-measures ANOVA was used to assess effects of bladder distension on 3-D tumor volume measurements. Repeatability of measurements was estimated via the coefficient of variation for each method.

Results—Repeatability was considered good for all 3 methods. There was no significant difference in tumor volume measurements obtained via 3-D ultrasonography at different degrees of urinary bladder distension. Results of Deming regression and Bland-Altman plots indicated excellent agreement between tumor volume measurement with 3-D ultrasonography and CT, but not between 2-D ultrasonography and CT.

Conclusions and Clinical Relevance—Tumor volume in dogs with TCC of the urinary bladder was accurately measured via 3-D ultrasonography. Use of 3-D ultrasonography can provide a less expensive and more practical method for monitoring response to treatment than CT and was more accurate than 2-D ultrasonography.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine whether 4 mg of estradiol cypionate (ECP) administered prophylactically to highrisk postparturient dairy cows decreases incidence of postpartum metritis.

Design—Randomized, placebo-controlled, triplemasked clinical trial.

Animals—250 postparturient dairy cows in a herd with postparturient hypocalcemia, retained fetal membranes, dystocia, stillbirth, or twins.

Procedure—Cows were given 4 mg of ECP (treatment) or 2 mL of vegetable oil (control) by IM injection within 24 to 36 hours of calving. Monitoring rectal temperatures and evaluation for metritis was performed once daily for 10 days. Cows with fever ≥ 39.7°C (103.5°F) were treated with 1.5 g of ceftiofur hydrochloride.

Results—When assessed by ordinal logistic regression, there were no differences between groups in incidence of mild or severe metritis. Cows that calved during the second or third quarter of the year were at increased risk of metritis, compared with those that calved during the fourth quarter. Following stratification by lactation (first and ≥ 2), it was observed that multiparous cows that did not receive antimicrobials during the first 3 days of the postparturient period were 5 times as likely to have metritis, compared with cows treated with antimicrobials on the basis of fever or other concurrent disease.

Conclusions and Clinical Relevance—Prophylactic administration of ECP to dairy cows at high risk for metritis did not reduce risk for metritis. Treating multiparous cows with antimicrobials on the basis of fever during the early postpartum period was associated with decreased incidence of metritis. (J Am Vet Med Assoc 2003;223:846–851)

Full access
in Journal of the American Veterinary Medical Association

SUMMARY

The effect of hypercapnia on the arrhythmo-genic dose of epinephrine (ADE) was investigated in 14 horses. Anesthesia was induced with guaifenesin and thiamylal sodium and was maintained at an end-tidal halothane concentration between 0.86 and 0.92%. Base-apex ECG, cardiac output, and facial artery blood pressure were measured and recorded. The ADE was determined at normocapnia (arterial partial pressure of carbon dioxide [Paco2 = 35 to 45 mm of Hg), at hypercapnia (Paco2 = 70 to 80 mm of Hg), and after return to normocapnia. Epinephrine was infused at arithmetically spaced increasing rates (initial rate = 0.25 μg/kg of body weight/min) for a maximum of 10 minutes. The ADE was defined as the lowest epinephrine infusion rate, to the nearest 0.25 μg/kg/min, at which 4 premature ventricular complexes occurred in a 15-second period. The ADE (mean ± SD) during hypercapnia (1.04 ± 0.23 μg/kg/min) was significantly (P < 0.05) less than the ADE at normocapnia (1.35 ± 0.38 μg/kg/min), whereas the ADE after return to normocapnia (1.17 ± 0.22 μg/kg/min) was not significantly different from those during normocapnia or hypercapnia. Baseline systolic and diastolic arterial pressures and cardiac output decreased after return to normocapnia. Significant differences were not found in arterial partial pressure of O2 (PaO2) or in base excess during the experiment. Two horses developed ventricular fibrillation and died during normocapnic determinations of ADE. Hypercapnia was associated with an increased risk of developing ventricular arrhythmias in horses anesthetized with guaifenesin, thiamylal sodium, and halothane.

Free access
in American Journal of Veterinary Research