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in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine whether bulk-tank standard plate counts or plate loop counts and bulk-tank somatic cell counts (SCC) were associated with detection of violative antimicrobial residues in milk from dairy cattle.

Design—Longitudinal study.

Procedure—Information for 1994 through 1997 was obtained from a large milk marketing cooperative that operated in multiple states throughout the northeastern and midwestern United States (16,831 herd-years of information from 6,546 farms) and from the Ohio Department of Agriculture Grade-A Milk Certification Program (12,042 herd-years of information from 4,022 farms). Data were analyzed by use of multivariate logistic regression.

Results—For both data sets, odds that a violative antibiotic residue would be detected increased as mean SCC for the herd-year increased. Standard plate counts and plate loop counts were not associated with odds that a violative antibiotic residue would be detected.

Conclusions and Clinical Relevance—Results of this study suggested that the odds that a violative antibiotic residue would be found in bulk-tank milk increased as mean SCC for the herd-year increased. This suggests that management practices that would be expected to influence SCC may also influence the risk of antibiotic residue violations. (J Am Vet Med Assoc 2000;217:541–545)

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in Journal of the American Veterinary Medical Association

Summary

Passive coxofemoral joint laxity of dogs, as quantitated by a distraction-stress radiographic method, may have important prognostic value in determining susceptibility to hip dysplasia. Data from 151 dogs, representing 13 breeds, were included in a logistic regression model to evaluate the contribution of factors such as age, breed, weight, sex, distraction index, and Norberg angle to the risk of developing degenerative joint disease (djd) of the coxofemoral joint. Of the factors studied, the amount of passive hip laxity, as quantitated by the distraction index, was the most significant (P < 0.0001) determinant of the risk to develop djd of the coxofemoral joint. In the longitudinal and crosssectional components of the study, distraction index was a significant (P < 0.001) risk factor for djd, irrespective of age at evaluation (4, 12, or 24 months). The strength of the hip laxity:djd correlation increased with the age of dog. In contrast, the Norberg angle, a measure of hip laxity on the standard hip-extended radiograph, was not found to be a significant risk factor for djd, either in the longitudinal or cross-sectional analyses. Breed-specific probability curves of djd susceptibility indicated that German Shepherd Dogs had a significantly (P < 0.05) greater risk of developing djd than did the pool of non-German Shepherd Dogs. The information derived from this statistical model will help to scientifically characterize the role of passive hip laxity as a component in the pathogenesis of djd of the coxofemoral joint.

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in Journal of the American Veterinary Medical Association

Summary

Passive laxity of the coxofemoral joints, as measured quantitatively by radiographing the joints under stress, has been shown to be an accurate measure of the risk for developing degenerative joint disease (djd) of the coxofemoral joints. Seventy-four Rottweilers between 12 and 40 months old were evaluated subjectively for radiographic evidence of djd, using the ventrodorsal view of the pelvis with the coxofemoral joints fully extended and the knees internally rotated (standard hip-extended view). Effect of age, sex, weight, and distraction index on the risk of developing djd was evaluated by use of a logistic regression model. Results were compared with those from a group of German Shepherd Dogs. Results indicated that in Rottweilers the distraction index was the only statistically significant predictor of the risk of developing djd of the coxofemoral joint. When German Shepherd Dogs were included in the model, they had a significantly greater risk of developing djd than did Rottweilers. This finding provides further support for the theory that there are differences in disease susceptibility among breeds and emphasizes the need to develop disease susceptibility curves for all breeds affected by hip dysplasia to facilitate accurate, scientifically based recommendations for breeding or treatment.

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in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Objective

To investigate the association between hip dysplasia (HD) and medial patellar luxation (MPL) in cats.

Design

Cross-sectional prevalence study.

Animals

78 cats.

Procedure

A complete history was obtained. Cats were examined to detect MPL and HD. Radiographs of the stifle and hip joints were obtained. Hip joints were evaluated by use of Norberg angle, distraction index, and scoring consistent with that established by the Orthopedic Foundation for Animals.

Results

There were 43 male and 35 female cats (mean age, 2.5 years). Eleven cats had clinical signs of disease in the pelvic limbs. Medial subluxation of the patella (subgrade 1) was seen in 31 of 33 cats with otherwise normal stifle joints. Medial patellar luxation was found in 45 of 78 (58%) cats, and 35 of 45 (78%) had grade-1 MPL. Bilateral MPL was seen in 32 of 45 (71%) cats. A weak association existed between MPL and HD, because cats were 3 times more likely to have HD and patellar luxation than to have either condition alone. Concurrent MPL and HD were detected in 19 of 78 (24%) cats, and HD was diagnosed radiographically in 25 of 78 (32%) cats (19 mild, 4 moderate, 2 severe). Eighteen of the 25 cats with HD had bilateral HD.

Conclusions and Clinical Relevance

Clinically normal cats may have a certain degree of laxity in the stifle joint, evident as medial patellar subluxation (< grade 1). There is a weak association between MPL and HD, and both conditions may develop, alone or in combination, more frequently than has been reported. (J Am Vet Med Assoc 1999;215:40-45)

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in Journal of the American Veterinary Medical Association

Objective

To determine whether results of the Ortolani method of hip joint palpation in dogs were related to distraction index (DI), Norberg angle, or radiographic hip score.

Design

Cross-sectional study.

Animals

459 clinically normal dogs.

Procedure

Dogs were sedated for radiography and palpation of the hip joints. Results of hip joint palpation were classified as negative, mild positive, moderate positive, or severe positive. Distraction indices were measured for all dogs. Norberg angles were measured for 380 dogs for which ventrodorsal hip-extended radiographic projections were available. Hip scores assigned by the Orthopedic Foundation for Animals (OFA) were available for 95 dogs.

Results

Age, weight, and sex were not significantly associated with results of hip joint palpation. There was moderate correlation between results of hip joint palpation and DI (r = 0.636), low-moderate correlation between results of hip joint palpation and OFA hip scores (rs = 0.437), and weak negative correlation (r = -0.236) between results of hip joint palpation and Norberg angle. For joints without degenerative joint disease (DJD), there was a significant linear relationship between results of hip palpation and DI; however, for joints with DJD, there was not. Results of hip joint palpation were 5.3-fold as likely to be negative for dogs with DJD as for dogs without.

Clinical Implications

Results of hip joint palpation were at best moderately correlated with radiographic measures of hip joint laxity. Therefore, hip joint palpation should be combined with hip-extended and stress radiography when assessing hip joint quality. (J Am Vet Med Assoc 1999;214:497–501).

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in Journal of the American Veterinary Medical Association

Abstract

Objective

To investigate the in vitro load/displacement characteristics of the hip joints in dogs as a function of joint position.

Sample Population

10 hip joints from 5 healthy dogs.

Procedure

A material test system was used to generate load/displacement curves for each joint. Joints were mounted in a custom-designed jig that held the joint in fixed anatomic orientations while plotting displacement and corresponding applied loads. All hips were cycled between 40 N of compression and 80 N of distraction. Each hip was tested at 10° increments from 30° flexion to 70° extension.

Results

When the hips were in a neutral orientation (approximately a standing position), load/displacement curves were characteristically sigmoidal (tri-phasic), indicating that, in this position, displacement was not highly dependent on load. The curves had a central low-stiffness region in which most of the lateral displacement took place. In contrast, when hips were positioned at the extremes of flexion and extension, this central, low-stiffness region was less distinct, and load/displacement curves were more linear, indicating a proportional relation between load and displacement. The load/displacement curve of 1 hip joint in the study deviated markedly from the others in a pattern consistent with cavitation of the synovial fluid.

Conclusions

When the hip joint is positioned in a neutral position, load-displacement behavior is sigmoidal, whereas when the hip joint is in an extended position, load/displacement behavior is more linear.

Clinical Relevance

Establishing load/displacement behavior of the hip joints in dogs was an important exercise in establishing the position for and estimating the repeatability of a clinical stress-radiographic method for quantitating joint laxity in dogs. (Am J Vet Res 1997;58:1078–1082)

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in American Journal of Veterinary Research

Summary

To provide long-term gastric fistulas for collection of third-compartment gastric contents, Janeway mucosal tube gastrostomy was performed, using a gastrointestinal stapling instrument, in 6 castrated adult male llamas. Mean operative time (±sem) was 65 ±4.16 minutes. All llamas survived the 6-week study period. Of the 6 llamas, 5 did not have signs of abdominal pain and returned to preoperative food consumption amounts within 36 hours. One llama had mild intermittent signs of abdominal pain daily for 7 days before returning to preoperative amount of food consumption. All gastrostomies leaked small amounts of gastric contents around indwelling 6- to 8-mm cannulas at the skin surface. Gastric contents did not leak when cannulas were dislodged from gastrostomy stomas. Replacement of cannulas was rapid and easy. Gravity-flow sample collection was best accomplished through 8-mm cannulas. Mean (±sem) weight loss was detected in all llamas (15 ± 3 kg) and was associated with frequent nonfeeding and stress of sample collection.

Gross necropsy findings were unremarkable in 5 of 6 llamas. All mucosal tube gastrostomies were patent, and there was no evidence of peritonitis. One llama had a single fibrous adhesion connecting the operative site with the ascending colon. Histologically, small (2.5- to 15-mm diameter) partial-thickness mucosal erosions identified at the tube gastrostomy-gastric wall junctions may have been associated with indwelling gastric cannulas. The Janeway gastrostomy was generally well tolerated in the llamas and should be considered as a useful long-term fistulation technique.

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in American Journal of Veterinary Research