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Objective—To identify predictors of veterinary students and veterinarians having an interest in veterinary public health and epidemiology (PH&E).

Design—Cross-sectional study.

Sample Population—Veterinary students enrolled in the College of Veterinary Medicine and Biomedical Sciences at Texas A&M University and veterinarians with membership in a Texas veterinary professional organization.

Procedures—2 questionnaires were designed and administered to investigate hypothesized predictors of PH&E interests among veterinary students and veterinarians. Descriptive statistics were calculated for all variables from both questionnaires. Prevalence ratios, 95% confidence intervals, and χ2 tests were used to evaluate bivariate associations between variables and an interest in PH&E. Multivariable logistic regression was used to adjust for the effects of multiple variables on the outcome.

Results—70% (215/305) of students believed that a course in PH&E was necessary, and 46% (140/304) believed that more courses in PH&E would improve the veterinary curriculum. Ninety-nine percent (299/303) of veterinarians believed that a course in PH&E was necessary in the curriculum. Ninety-two percent (272/297) of veterinarians agreed that knowledge related to PH&E was important to perform the functions of their job. History of raising animals and membership in 4-H or Future Farmers of America were significant predictors of veterinary students having an interest in PH&E. Being male and growing up in a rural environment were not significant predictors.

Conclusions and Clinical Relevance—Most veterinary students and veterinarians agreed that knowledge of PH&E is important. Variables identified as associated with an interest in PH&E may be useful for designing mitigation strategies to increase the number of veterinarians entering public health careers.

Full access
in Journal of the American Veterinary Medical Association


Objective—To determine whether West Nile virus (WNV) disease hyperendemic foci (hot spots) exist within the horse population in Texas and, if detected, to identify the locations.

Sample Population—Reports of 1,907 horses with WNV disease in Texas from 2002 to 2004.

Procedures—Case data with spatial information from WNV epidemics occurring in 2002 (1,377 horses), 2003 (396 horses), and 2004 (134 horses) were analyzed by use of the spatial scan statistic (Poisson model) and kriging of empirical Bayes smoothed county attack rates to determine locations of horses with WNV disease in which affected horses were consistently (in each of the 3 study years) clustered (hyperendemic foci, or hot spots).

Results—2 WNV hot spots in Texas, an area in northwestern Texas and an area in eastern Texas, were identified with the scan statistic. Risk maps of the WNV epidemics were qualitatively consistent with the hot spots identified.

Conclusions and Clinical Relevance—WNV hot spots existed within the horse population in Texas (2002 to 2004). Knowledge of disease hot spots allows disease control and prevention programs to be made more efficient through targeted surveillance and education.

Full access
in American Journal of Veterinary Research


Objective—To evaluate the seroprevalence of paratuberculosis by use of 2 commercial ELISAs in association with prevalence of fecal shedding of mycobacteria within beef cattle herds.

Design—Cross-sectional field study.

Animals—Six beef herds (affected herds; 522 cattle) with and 3 geographically matched herds (181 cattle) without high seroprevalence of paratuberculosis.

Procedures—Blood and fecal samples were collected from adult cattle and assessed for serum anti–Mycobacterium avium subsp paratuberculosis (MAP) antibodies with 2 commercial ELISA kits and submitted for bacterial culture for MAP and environmental bacteria (termed environmental mycobacteria) via a radiometric method, respectively. Species of mycobacterial isolates were identified, and sensitivities and specificities of the 2 ELISAs were compared.

Results—Compared with comparison cattle, cattle from affected herds were 9.4 times as likely to have environmental mycobacteria isolated from feces. Among the 6 affected and 3 comparison herds, the proportions of cattle shedding environmental mycobacteria were 0.225 (range, 0.1 to 0.72) and 0.04 (range, 0 to 0.06), respectively. Although relative MAP-detection specificities (compared with bacterial culture of feces) were different between the 2 ELISAs, sensitivities were not. Nine environmental mycobacterial species were iden-tified from participating herds. All affected herds apparently had ≥ 1 bovid infected with MAP, although MAP was not isolated from any cattle in comparison herds.

Conclusions and Clinical Relevance—In beef herds with persistently high rates of false-positive ELISA results, which may be associated with recovery of environmental myco-bacteria from feces, organism detection via bacterial culture of feces or PCR assay should direct paratuberculosis control measures.

Full access
in Journal of the American Veterinary Medical Association


Objective—To evaluate the effect of exposure to environmental mycobacteria on results of 2 commercial ELISAs for paratuberculosis in cattle.

Design—Experimental trial.

Animals—19 weaned crossbred beef calves.

Procedures—Calves were inoculated SC with 1 of 5 mycobacterial isolates (3 calves/isolate) derived from herds with high proportions of false-positive serologic reactions for paratuberculosis, Mycobacterium avium subsp paratuberculosis (MAP; positive control inoculum; 2 calves), or mineral oil (negative control inoculum; 2 calves). Sera were assessed at intervals by use of 2 ELISAs (A and B) for paratuberculosis in cattle, and all calves underwent tuberculosis testing at the end of the study.

Results—Neither mineral oil–inoculated calf had positive results with either ELISA during the study. Both MAP-inoculated calves were identified as seropositive via ELISA-A, and 1 calf was identified as seropositive via ELISA-B. By use of ELISA-A, ≥ 1 false-positive reaction over time was detected in 2, 3, 3, and 1 of the 3 calves injected with Mycobacterium avium, Mycobacterium intracellulare, Mycobacterium scrofulaceum, or Mycobacterium terrae, respectively. By use of ELISA-B, only M scrofulaceum induced false-positive reactions (2/3 calves). Calves that had at least 1 positive ELISA-A result were more likely to be classified as suspect reactors via the caudal fold tuberculosis test.

Conclusions and Clinical Relevance—False-positive serologic reactions may occur during use of commercially available ELISAs for paratuberculosis in calves experimentally exposed to environmental mycobacteria; naturally occurring exposures with these mycobacteria may represent a cause for high proportions of false-positive serologic reactions for paratu-berculosis in some cattle herds.

Full access
in Journal of the American Veterinary Medical Association


Objective—To determine whether body weight, body condition score, or various body dimensions were associated with acute thoracolumbar intervertebral disk extrusion or protrusion and whether any of these factors were associated with severity of clinical signs in Dachshunds.

Design—Cross-sectional clinical study.

Animals—75 Dachshunds with (n = 39) or without (36) acute thoracolumbar intervertebral disk extrusion or protrusion.

Procedures—Signalment, various body measurements, body weight, body condition score, and spinal cord injury grade were recorded at the time of initial examination.

Results—Mean T1-S1 distance and median tuber calcaneus–to–patellar tendon (TC-PT) distance were significantly shorter in affected than in unaffected dogs. A 1-cm decrease in T1-S1 distance was associated with a 2.1-times greater odds of being affected, and a 1-cm decrease in TC-PT distance was associated with an 11.1-times greater odds of being affected. Results of multivariable logistic regression also indicated that affected dogs were taller at the withers and had a larger pelvic circumference than unaffected dogs, after adjusting for other body measurements. Results of ordinal logistic regression indicated that longer T1-S1 distance, taller height at the withers, and smaller pelvic circumference were associated with more severe spinal cord injury.

Conclusions and Clinical Relevance—Results suggest that certain body dimensions may be associated with acute thoracolumbar intervertebral disk extrusion or protrusion in Dachshunds and, in affected dogs, with severity of neurologic dysfunction.

Full access
in Journal of the American Veterinary Medical Association


Objective—To estimate the sensitivity (Se) and specificity (Sp) for an enhanced direct-fecal PCR procedure, bacterial culture of feces (BCF), and a serum ELISA for detecting Mycobacterium avium subsp paratuberculosis (MAP) infection in adult dairy cattle.

Sample Population—Fecal and serum samples were collected from 669 adult cattle randomly selected from a 4,000-cow dairy herd known to contain animals infected with MAP.

Procedures—Serum samples were evaluated for MAP-specific antibodies via ELISA. Fecal samples were evaluated by BCF and enhanced PCR methods (both gel-based [GB]-PCR and quantitative real-time [qRT]-PCR assays). Fecal samples also were pooled (5:1) and then subjected to GB-PCR assay. Bayesian statistical methods were used to estimate Se and Sp for each diagnostic test without knowledge concerning true MAP infection status.

Results—Adjusting for Se conditional dependence between serum ELISA and BCR, overall Se and Sp were estimated at 33.7% and 95.9%, 51.3% and 99.0%, and 32.2% and 100% for serum ELISA, qRT-PCR, and BCF, respectively.The GB-PCR assay yielded positive results for 38.3% of the pools known to contain feces from at least 1 cow that had positive GBPCR results.

Conclusions and Clinical Relevance—Estimated Se values for the serum ELISA and BCF were slightly lower than those reported elsewhere. The enhanced qRT-PCR method offered relative improvements in Se of 52% and 59% over serum ELISA and microbial culture, respectively. Pooling of fecal samples and testing with the GB-PCR assay are not recommended. Additional studies with qRT-PCR and fecal pools are required.

Full access
in American Journal of Veterinary Research


Objective—To estimate associations between dietary factors and pancreatitis in dogs.

Design—Retrospective case-control study.

Animals—198 dogs with a clinical diagnosis of pancreatitis and 187 control dogs with a diagnosis of renal failure without clinical evidence of pancreatitis.

Procedures—Information on signalment, weight, body condition, dietary intake, medical history, diagnostic tests performed, concurrent diseases, treatments, duration of hospitalization, and discharge status was extracted from medical records. Information on dietary intake, signalment, weight, and medical, surgical, and environmental history was collected through a telephone questionnaire. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals.

Results—On the basis of information extracted from the medical record, ingesting unusual food items (OR, 4.3) increased the odds of pancreatitis. On the basis of information gathered through the telephone questionnaire, ingesting unusual food items (OR, 6.1), ingesting table scraps the week before diagnosis (OR, 2.2) or throughout life (OR, 2.2), and getting into the trash (OR, 13.2) increased the odds of pancreatitis. Multivariable modeling indicated that reporting exposure to ≥ 1 dietary factor during the telephone questionnaire (OR, 2.6), being overweight (OR, 1.3) or neutered (OR, 3.6), previous surgery other than neutering (OR, 21.1), and the interaction between neuter status and previous surgery other than neutering (OR, 0.1) were associated with the odds of pancreatitis.

Conclusions and Clinical Relevance—Results suggested that dietary factors, being neutered, and previous surgery other than neutering increased the odds of pancreatitis in dogs.

Full access
in Journal of the American Veterinary Medical Association



African Horse Sickness (AHS) is a vector-borne disease endemic to sub-Saharan Africa caused by African Horse Sickness Virus (AHVS). Infections in naïve horses have high morbidity and mortality rates. AHS pathogenesis is not well understood; neither the hematologic changes nor acute phase response occurring during infection has been fully evaluated. The study’s objective was to characterize the hematologic changes and acute phase response during experimental infection with AHSV.


4 horses negative for AHSV group-specific antibodies.


In this prospective, longitudinal study conducted between November 23 and December 2, 2020, horses were experimentally infected with AHSV, and blood samples were obtained before inoculation and then every 12 hours until euthanasia. Hematologic changes and changes for serum amyloid A (SAA) and iron concentration were evaluated over time using a general linear model including natural logarithm of sampling time.


All horses were humanely euthanized due to severe clinical signs typical of AHS. Median Hct increased significantly, and the median WBC count, monocyte count, eosinophil count, and myeloperoxidase index changed significantly in all horses over time. Horses developed marked thrombocytopenia (median, 48 X 103 cells/µL; range, 21 X 103 to 58 X 103 cells/µL) while markers of platelet activation also changed significantly. Median SAA increased and serum iron concentration decreased significantly over time.


Results indicated severe thrombocytopenia with platelet activation occurs during infection with AHSV. Changes in acute phase reactants SAA and iron, while significant, were unexpectedly mild and might not be useful clinical markers.

Open access
in American Journal of Veterinary Research


Objective—To compare calf weaning weight and associated economic variables for beef cows with serum antibodies against Mycobacterium avium subsp paratuberculosis (MAP) or from which MAP was isolated from feces with those for cows that were seronegative for antibodies against or culture negative for MAP.

Design—Retrospective study.

Animals—4,842 beef cows from 3 herds enrolled in the USDA National Johne's Disease Demonstration Herd Project.

Procedures—Individual cow ELISA and culture results were obtained from the project database. During each parity evaluated for each cow, the 205-day adjusted weaning weight (AWW) of its calf was calculated. The AWW was compared between test-positive and test-negative cows by use of multilevel mixed-effect models. The median value for feeder calves from 2007 to 2011 was used to estimate the economic losses associated with MAP test–positive cows.

Results—The AWW of calves from cows with strongly positive ELISA results was 21.48 kg (47.26 lb) less than that of calves from cows with negative ELISA results. The AWW of calves from cows classified as heavy or moderate MAP shedders was 58.51 kg (128.72 lb) and 40.81 kg (89.78 lb) less, respectively, than that of calves from MAP culture–negative cows. Associated economic losses were estimated as $57.49/calf for cows with strongly positive ELISA results and $156.60/calf and $109.23/calf for cows classified as heavy and moderate MAP shedders, respectively.

Conclusions and Clinical Relevance—Calves from cows with MAP-positive test results had significantly lower AWWs than did calves from cows with MAP-negative test results, which translated into economic losses for MAP-infected beef herds.

Full access
in Journal of the American Veterinary Medical Association


OBJECTIVE To estimate reliability of interpretation of neurologic examination findings for localization of vestibular dysfunction in dogs.

DESIGN Cross-sectional study.

ANIMALS 496 dogs that underwent MRI of the head for diagnosis of a neurologic problem between September 2011 and September 2015.

PROCEDURES Medical records were reviewed and data collected regarding signalment and neurologic examination, MRI, and CSF findings. Independent observers interpreted the findings, and agreement was assessed for a subset of dogs. Distributions of variables were compared between dogs with and without a neurologic findings–based interpretation of vestibular disease.

RESULTS 37% (185/496) of dogs had signs of vestibular dysfunction, of which 82% (151/185) had MRI abnormalities. In 73% (110/151) of dogs with MRI abnormalities, lesions involved central vestibular structures, and in 19% (29/151), lesions involved peripheral vestibular structures. On the basis of neurologic findings interpretation, 86% (160/185) of dogs were classified as having central vestibular dysfunction, and 61% (98/160) of these had an MRI-identified central vestibular lesion. Agreement among 3 independent observers was good (κ = 0.72) regarding use of neurologic examination findings to diagnose central versus peripheral vestibular dysfunction and very good (κ = 0.85) regarding use of MRI to diagnose peripheral vestibular lesions. Despite this agreement, only 29% (7/24) of dogs with a consensus clinical interpretation of peripheral vestibular dysfunction had MRI-identified peripheral lesions.

CONCLUSIONS AND CLINICAL RELEVANCE Although interobserver agreement was good for distinguishing central from peripheral vestibular dysfunction in dogs through interpretation of neurologic examination findings, this interpretation did not agree with the MRI-based diagnosis.

Full access
in Journal of the American Veterinary Medical Association