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Abstract

Objective—

To determine normal adrenal gland size by means of ultrasonography in dogs and to determine the value of ultrasonography in the diagnosis of pituitary-de-pendent hyperadrenocorticism (PDH) in dogs.

Design—

Prospective observational study.

Animals—

62 dogs: 20 healthy dogs, 20 dogs with non-endocrine disease, and 22 dogs with untreated PDH.

Procedure—

Length and maximum and minimum diameter of the adrenal glands were measured ultrasonographically. Multiple regression and correlation analyses were used to determine whether body weight, kidney length, aortic diameter, or age was related to adrenal gland size. Two-tailed t-tests and multiple linear regression analysis were used to compare values between groups. Sensitivity and specificity of using ultrasonographic measurement of adrenal gland size as a diagnostic test for PDH were determined.

Results—

There was a significant linear relationship between adrenal gland length, but not maximum and minimum diameters, and body weight, aortic diameter, and kidney length in healthy dogs and in dogs with nonenocrine diseases. Length, maximum diameter, and minimum diameter of the right adrenal gland and maximum and minimum diameters of the left adrenal gland were significantly greater in dogs with PDH than in healthy dogs and dogs with nonendocrine diseases. As a diagnostic test for pdh, ultrasonographic measurement of maximum or minimum diameter of the left adrenal gland gave the best combination of sensitivity and specificity. For maximum diameter of the left adrenal gland, sensitivity was 77% and specificity was 80%. For minimum diameter of the left adrenal gland, sensitivity was 73% and specificity was 85%.

Clinical Implication—

Ultrasonography of the adrenal glands is a valuable diagnostic procedure in dogs suspected of having pituitary-dependent hyperadrenocorticism.

Free access
in Journal of the American Veterinary Medical Association

Summary

Topically administered tissue plasminogen activator (tPA) was evaluated for its penetration into aqueous humor of clinically normal dogs. Two concentrations of tPA (5 mg/ml and 10 mg/ml) were evaluated in a single-dose study, and a concentration of 5 mg of tPA/ml was used for a multiple-dose study. The contralateral eye served as a nontreated control. Enzyme substrate analysis of aqueous humor was used to determine tPA activity. The activity of tPA in aqueous humor was significantly (P ≤ 0.05) greater in treated eyes of all dogs, compared with that in control eyes. Significant differences in activity of tPA were not detected at different doses in treated eyes.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate various sampling strategies for potential use in measuring prevalence of antimicrobial susceptibility in cattle.

Sample Population—500 isolates of non–type-specific Escherichia coli (NTSEC) isolated from the feces of 50 cows from 2 dairy farms (25 cows/farm and 10 isolates/cow).

Procedures—Diameters of inhibition zones for 12 antimicrobials were analyzed to estimate variation among isolates, cows, and farms and then used to determine sampling distributions for a stochastic simulation model to evaluate 4 sampling strategies. These theoretic sampling strategies used a total of 100 isolates in 4 allocations (1 isolate from 100 cows, 2 isolates from 50 cows, 3 isolates from 33 cows, or 4 isolates from 25 cows).

Results—Analysis of variance composition revealed that 74.2% of variation was attributable to isolates, 18.5% to cows, and 7.3% to farms. Analysis of results of simulations suggested that when most of the variance was attributable to differences among isolates within a cow, culturing 1 isolate from each of 100 cows underestimated overall prevalence, compared with results for culturing more isolates per cow from fewer cows. When variance was not primarily attributable to differences among isolates, all 4 sampling strategies yielded similar results.

Conclusions and Clinical Relevance—It is not always possible to predict the hierarchical level at which clustering will have its greatest impact on observed susceptibility distributions. Results suggested that sampling strategies that use testing of 3 or 4 isolates/cow from a representative sample of all animals better characterize herd prevalence of antimicrobial resistance when impacted by clustering.

Full access
in American Journal of Veterinary Research

Abstract

Case Description—A 2-year-old spayed female domestic shorthair cat was examined because of bilateral thoracic limb weakness of acute onset.

Clinical Findings—Clinical signs included muscle atrophy, paresis, depressed spinal reflexes, hyperesthesia of the thoracic limbs, and reduced jaw muscle tone. Pelvic limb reflexes were normal. Results of a neurologic examination were suggestive of multifocal lesions involving both brachial plexuses and the trigeminal nerves. Abnormal nerve conduction across the brachial plexus and delayed late potentials were found on electrodiagnostic testing, and diffuse subclinical involvement of other regions of the peripheral nervous system was confirmed on the basis of abnormal electromyographic findings for the masticatory muscles and conduction block of the peroneal nerve.

Treatment and Outcome—No specific treatments were given, and neurologic signs resolved within a month. A relapse occurred 2 months after the first episode, with clinical signs affecting both the pelvic and the thoracic limbs on this occasion. Again, the condition resolved without specific treatment, and 13 months after the initial episode, the cat reportedly was normal.

Conclusions and Clinical Relevance—Findings suggested that brachial plexus neuropathy can be a multifocal disease in cats, even if clinically apparent neurologic deficits are initially subtle or absent, and that electrodiagnostic techniques can be used to identify subclinical involvement of the peripheral nerves.

Full access
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE

To evaluate and compare the prognosis for Thoroughbred racehorses to return to galloping and racing with injuries to the palmaroproximal metacarpus diagnosed with MRI.

ANIMALS

29 flat racing Thoroughbreds at the Hong Kong Jockey Club that underwent MRI between 2014 and 2022.

METHODS

Clinical, radiographic, ultrasonographic, and MRI reports were collected from veterinary clinical records, and these were combined with training and racing data. Horses were categorized on the basis of MRI diagnosis: (1) proximal suspensory ligament (PSL) involvement only, (2) PSL and concurrent proximal third metacarpal (MC3) bone involvement, and (3) proximal MC3 bone involvement only. The following were compared for prognosis for return to athletic function: return to galloping or racing, and reinjury.

RESULTS

Overall, the prognosis for return to athletic function was fair, with 92% (22/24; P = .53) and 67% (16/24; P = .73) of horses returning to galloping and racing, respectively. There was a relatively low reinjury rate, with 18% (4/22) of horses reinjuring. Horses with concurrent injury to both the PSL and proximal MC3 bone (Category 2) took longer to return to gallop (median, 116; IQR, 100.5 to 160), when compared with horses having only PSL injury (median, 69; IQR, 43 to 80; P = .04). Of the 4 horses that reinjured, 3 (75%) were horses in Category 2.

CLINICAL RELEVANCE

The findings from this study suggest that injuries involving both PSL and proximal MC3 bone concurrently require a longer rehabilitation period than those with PSL involvement alone.

Open access
in Journal of the American Veterinary Medical Association

Objective—

To determine the effect of administration of vitamin E (D-α-tocopherol) on the incidence of retained placenta, metritis, and clinical mastitis during early lactation and on tocopherol concentrations.

Design—

Prospective randomized controlled study.

Animals—

420 Holstein cows

Procedure—

Vitamin E (3,000 mg, IM, once) was administered to 204 cows 8 to 14 days before expected parturition, and 216 control cows were not treated. The number of cows that had retained placenta, metritis, clinical mastitis, displaced abomasum, and clinically apparent acetonemia or hypocalcemia were recorded. Serum concentrations of tocopherol, the tocopherol:cholesterol ratio, and glutathione-peroxidase activity were determined from samples obtained before administration of vitamin E, 7 and 14 days after administration, and at 30 days after parturition from 36 treated and 36 control cows.

Results—

Administration of vitamin E significantly decreased the incidence of retained placenta and metritis (13/204 [6.4%] and 8/204 [3.9%], respectively, for the vitamin E-treated group; 27/216 [12.5%] and 19/216 [8.8%], respectively, for the untreated group) but did not affect the incidence of clinical mastitis. Serum vitamin E concentration was significantly higher in treated than in control cattle at 7 and 14 days after administration, but serum tocopherohcholesterol ratio was significantly higher only at 7 days after administration.

Clinical Implications—

Parenteral administration of a single injection of vitamin E before parturition may decrease the incidence of retained placenta and metritis in dairy cows but will increase serum concentrations for 7 to 14 days after administration. (J Am Vet Med Assoc 1997;211:466–469)

Free access
in Journal of the American Veterinary Medical Association

Summary

Data were collected from 104 Minnesota swine farms quarantined for pseudorabies virus (prv) infection. Each herd was serologically evaluated for the presence of antibodies to prv in finishing pigs. Herd management practices, swine housing design, and disease profiles were described for each farm. Multiple logistic regression analysis was used to determine which factors were associated with circulation of prv in the finishing pigs of farrow-to-finish farms. Sixty-seven (64%) of the herds had no serologic evidence of prv circulation in the finishing section, whereas 37 herds (36%) contained at least one prv seropositive finishing pig. The odds of a given finishing herd being seropositive for prv were 2.85 times higher if the finishing pigs were housed in confinement (P = 0.01), 2 times higher if Actinobacillus (Haemophilus) pleuropneumoniae was a clinical problem in the herd (P = 0.03), 1.36 times less for each year that passed since the herd quarantine was issued (P = 0.01), 1.74 times higher if clinical signs of prv were reported (P = 0.04), and 1.52 times higher if animal protein was included in at least one of the rations (P = 0.08).

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate the effectiveness of various sampling techniques for determining antimicrobial resistance patterns in Escherichia coli isolated from feces of feedlot cattle.

Sample Population—Fecal samples obtained from 328 beef steers and 6 feedlot pens in which the cattle resided.

Procedure—Single fecal samples were collected from the rectum of each steer and from floors of pens in which the cattle resided. Fecal material from each single sample was combined into pools containing 5 and 10 samples. Five isolates of Escherichia coli from each single sample and each pooled sample were tested for susceptibility to 17 antimicrobials.

Results—Patterns of antimicrobial resistance for fecal samples obtained from the rectum of cattle did not differ from fecal samples obtained from pen floors. Resistance patterns from pooled samples differed from patterns observed for single fecal samples. Little pen-to-pen variation in resistance prevalence was observed. Clustering of resistance phenotypes within samples was detected.

Conclusions and Clinical Relevance—Studies of antimicrobial resistance in feedlot cattle can rely on fecal samples obtained from pen floors, thus avoiding the cost and effort of obtaining fecal samples from the rectum of cattle. Pooled fecal samples yielded resistance patterns that were consistent with those of single fecal samples when the prevalence of resistance to an antimicrobial was > 2%. Pooling may be a practical alternative when investigating patterns of resistance that are not rare. Apparent clustering of resistance phenotypes within samples argues for examining fewer isolates per fecal sample and more fecal samples per pen. (Am J Vet Res 2002;63:1662–1670)

Full access
in American Journal of Veterinary Research

Objective

To determine whether certain characteristics of dogs offered for adoption are associated with successful adoption.

Design

Retrospective cohort study.

Animals

1,468 relinquished dogs offered for adoption at a local humane society.

Procedure

Data regarding dogs offered for adoption were obtained from surveys completed by previous owners. Data were analyzed by use of bivariate statistics and multivariable logistic regression.

Results

Of dogs offered for adoption, 1,073 were successfully adopted, 239 were not adopted, and 157 were returned to the shelter after adoption. Terrier, hound, toy, and nonsporting breeds were found to be significantly associated with successful adoption (P< 0.05, χ2 analysis). Certain coat colors (gold, gray, and white), small size, and history of an indoor environment were also significant predictors of successful adoption. The correlation coefficient (0.048) indicated that only a small percentage of variance in adoption success could be explained by the multiple logistic regression model.

Clinical Implications

Animal shelter managers with limited kennel capacity may wish to periodically use surveys to determine whether the type of dog being offered to the public reflects the type of dog the public will adopt. (J Am Vet Med Assoc 1998;213:478-482)

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the prevalence, fecal shedding pattern, and association of bovine torovirus (BoTV) with diarrhea in veal calves at time of arrival and periodically throughout the first 35 days after their arrival on a veal farm.

Animals—62 veal calves.

Procedure—Fecal samples collected on days 0, 4, 14, and 35 after arrival were tested for BoTV by use of ELISA and reverse transcriptase-polymerase chain reaction (RT-PCR) assay. Paired serum samples obtained from blood collected on days 0 and 35 were analyzed for BoTV antibodies with a hemagglutination inhibition assay. Fecal samples were also screened for other enteric pathogens, including rotavirus, coronavirus, and Cryptosporidium spp.

Results—Fecal shedding of BoTV was detected in 15 of 62 (24%) calves by use of ELISA and RT-PCR assay, with peak shedding on day 4. A significant independent association between BoTV shedding and diarrhea was observed. In addition, calves shedding ≥ 2 enteric pathogens were more likely to have diarrhea than calves shedding ≤ 1 pathogen. Calves that were seronegative or had low antibody titers against BoTV (≤ 1:10 hemagglutination inhibition units) at arrival seroconverted to BoTV (> 4-fold increase in titer); these calves were more likely to shed virus than calves that were seropositive against BoTV at arrival.

Conclusions and Clinical Relevance—Shedding of BoTV was strongly associated with diarrhea in neonatal veal calves during the first week after arrival at the farm. These data provide evidence that BoTV is an important pathogen of neonatal veal calves. (Am J Vet Res 2003;64:485–490)

Full access
in American Journal of Veterinary Research