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  • Author or Editor: Thomas P. Gregor x
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Abstract

Objective—To evaluate the clinical response rate, progression-free survival time, overall survival time, and possible prognostic factors associated with a cyclophosphamide-, vincristine-, and prednisone (COP)-based chemotherapy protocol in cats with lymphoma.

Design—Retrospective case series.

Animals—114 cats with lymphoma.

Procedures—Medical records of cats receiving a weekly COP-based chemotherapy protocol from 1998 to 2008 at the Matthew J. Ryan Veterinary Hospital of the University of Pennsylvania were evaluated for information regarding signalment, anatomic site of involvement, cell morphology, treatment, and outcome. Retroviral status, baseline weight, substage, anatomic location, dose delays, dose reductions, and response to treatment were evaluated for prognostic importance.

Results—The majority of cases (94 [82.4%]) were substage b, and the most common anatomic site was the gastrointestinal tract (57 [50%]). Clinical response rate after the first chemotherapy cycle was 47.4%. Response to treatment was significantly associated with progression-free survival time and overall survival time, whereas substage was significantly associated with progression-free survival time. The median progression-free survival time and overall survival time were 65.5 and 108 days, respectively. Compared with nonresponders, responders had significantly longer median progression-free survival time (364 vs 31 days) and median overall survival time (591 vs 73 days).

Conclusions and Clinical Relevance—Clinical response after 1 cycle of COP-based chemotherapy was predictive for progression-free survival time and overall survival time in cats with lymphoma; therefore, response after 1 cycle of chemotherapy could be used to guide decisions about further treatment. No new prognostic factors were identified.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine effects of hip joint osteoarthritis on radiographic measures of hip joint laxity and congruence.

Design—Longitudinal study.

Animals—40 Labrador Retrievers.

Procedures—Dogs were assigned to 2 groups based on radiographic evidence of osteoarthritis. Dogs in the osteoarthritis group were free of osteoarthritis at initial radiographic evaluation (t1) and developed osteoarthritis by a subsequent radiographic evaluation (t2). Dogs in the nonosteoarthritis group had no radiographic osteoarthritis at either evaluation. Hip joint laxity was quantified by use of the distraction index (DI) from a distraction radiographic view and use of the Norberg angle (NA) from a ventrodorsal hip-extended radiographic view. The compression index (CI) from a compression radiographic view was used as a measure of joint congruence (concentricity).

Results—Hip joint laxity (NA or DI) did not change over time in the nonosteoarthritis group. Mean hip joint laxity (NA and DI) for the osteoarthritis group was greater at t1 than for the nonosteoarthritis group. With the onset of osteoarthritis, mean NA decreased significantly and mean CI increased significantly, but mean DI remained unchanged.

Conclusions and Clinical Relevance—No radiographic evidence for compensatory hip joint tightening associated with osteoarthritis was detected. Hip-extended radiography revealed that hip joints got looser with osteoarthritis and NA decreased. Hip joint laxity (DI) on distraction radiographs was unchanged by the onset of osteoarthritis and remained constant in the osteoarthritis and nonosteoarthritis groups at both evaluations. However, the CI increased with osteoarthritis, as reflected in nonzero indices (incongruence). The CI may be a valid marker for early hip joint osteoarthritis.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine whether age, breed, sex, weight, or distraction index (DI) was associated with the risk that dogs of 4 common breeds (German Shepherd Dog, Golden Retriever, Labrador Retriever, Rottweiler) would have radiographic evidence of degenerative joint disease (DJD) associated with hip dysplasia.

Design—Cross-sectional prevalence study.

Animals—15,742 dogs.

Procedure—Hips of dogs were evaluated radiographically by use of the ventrodorsal hip-extended view, the compression view, and the distraction view. The ventrodorsal hip-extended view was examined to determine whether dogs had DJD. For each breed, a multiple logistic regression model incorporating age, sex, weight, and DI was created. For each breed, disease-susceptibility curves were produced, using all dogs, regardless of age, and dogs grouped on the basis of age.

Results—Weight and DI were significant risk factors for DJD in all breeds. For German Shepherd Dogs, the risk of having DJD was 4.95 times the risk for dogs of the other 3 breeds combined. In all breeds, the probability of having DJD increased with age.

Conclusions and Clinical Relevance—Results indicated that the probability of having hip DJD increased with hip joint laxity as measured by use of DI. This association was breed-specific, indicating that breedspecific information on disease susceptibility should be incorporated when making breeding decisions and when deciding on possible surgical treatment of hip dysplasia. (J Am Vet Med Assoc 2001;219:1719–1724)

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the relationship between the caudolateral curvilinear osteophyte (CCO) and osteoarthritis associated with hip dysplasia in dogs.

Design—Longitudinal cohort study.

Animals—48 Labrador Retrievers from 7 litters.

Procedure—In each of 24 sex- and size-matched pairs fed the same diet, a restricted-fed dog was fed 25% less than a control dog for life. The dogs' hips were evaluated in the standard ventrodorsal hip-extended radiographic projection at 16, 30, and 52 weeks of age and then yearly for life. Histologic examination of hip joint tissues was performed on 45 dogs.

Results—Median age at death was 11.2 years. Adjusting for feeding group, dogs with a CCO were 3.7 times as likely to develop radiographic signs of osteoarthritis than those without a CCO. Stratified by diet, 100% of the control dogs with a CCO developed radiographic signs of osteoarthritis and 55% of restricted-fed dogs with a CCO developed radiographic signs of osteoarthritis. The CCO was the first radiographic change seen in 22 of 29 (76%) dogs with osteoarthritis. Overall, 35 of 37 (95%) dogs with a CCO had histopathologic lesions of osteoarthritis.

Conclusions and Clinical Relevance—Results indicate a relationship between a CCO on the femoral neck and subsequent development of radiographic signs of osteoarthritis in Labrador Retrievers evaluated over their life span. A CCO is an important early radiographic indication of osteoarthritis associated with canine hip dysplasia. (J Am Vet Med Assoc 2004;225:233–237)

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To compare 2 screening methods for detecting evidence of hip dysplasia (Orthopedic Foundation for Animals [OFA] and PennHIP) in dogs.

Design—Diagnostic test evaluation study.

Animals—439 dogs ≥ 24 months of age that received routine hip joint screening from June 1987 through July 2008.

Procedures—Dogs were sedated, and PennHIP radiography was performed (hip joint– extended [HE], compression, and distraction radiographic views). The HE radiographic view was submitted for OFA evaluation. A copy of the HE radiographic view plus the compression and distraction radiographic views were submitted for routine PennHIP evaluation, including quantification of hip joint laxity via the distraction index (DI).

Results—14% (60/439) of dogs had hip joints scored as excellent by OFA standards; however, 52% (31/60) of those had a DI ≥ 0.30 (range, 0.14 to 0.61). Eighty-two percent of (183/223) dogs with OFA-rated good hip joints had a DI ≥ 0.30 (range, 0.10 to 0.77), and 94% (79/84) of dogs with OFA-rated fair hip joints had a DI ≥ 0.30 (range, 0.14 to 0.77). Of all dogs with fair to excellent hip joints by OFA standards, 80% (293/367) had a DI ≥ 0.30. All dogs with OFA-rated borderline hip joints or mild, moderate, or severe hip dysplasia had a DI ≥ 0.30 (range, 0.30 to 0.83).

Conclusion and Clinical Relevance—Dogs judged as phenotypically normal by the OFA harbored clinically important passive hip joint laxity as determined via distraction radiography. Results suggested that OFA scoring of HE radiographs underestimated susceptibility to osteoarthritis in dogs, which may impede progress in reducing or eliminating hip dysplasia through breeding.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To estimate prevalence of canine hip dysplasia (CHD) in Golden Retrievers and Rottweilers and identify sources of bias in published reports.

Design—Prospective study.

Animals—200 clinically normal Golden Retrievers and 140 clinically normal Rottweilers between 24 and 60 months of age referred for hip evaluation (group 1) and 93 clinically normal dogs evaluated for Orthopedic Foundation for Animals (OFA) hip certification (group 2).

Procedure—Hip-extended pelvic radiographs from group 1 dogs were screened for CHD. Radiographs were evaluated twice; the first interpretation used an OFA-type subjective 7-point scoring system, and the second included the caudolateral curvilinear osteophyte as an additional sign of degenerative joint disease. The OFA submission rate of group 2 dogs was determined from the number of official reports returned from the OFA.

Results—Prevalence of CHD in Golden Retrievers ranged from 53% to 73% and in Rottweilers ranged from 41% to 69%. Among dogs referred for OFA evaluation, radiographs from 49 (53%) were submitted to OFA. Of submitted radiographs, 45 (92%) were normal; of radiographs not submitted, 22 (50%) were normal. Radiographs with normal-appearing hips were 8.2 times as likely to be submitted to the OFA. Compared with Golden Retrievers, Rottweiler radiographs were significantly more likely to be submitted for OFA certification.

Conclusions and Clinical Relevance—Prevalence of CHD in these 2 breeds may be much higher than previously reported in the United States. Results suggest substantial bias in the OFA database, which causes lower estimates of prevalence of CHD. (J Am Vet Med Assoc 2005;226:387–392)

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate hip joint laxity in 10 breeds of dogs via 2 radiographic techniques.

Animals—500 clinically normal dogs.

Design—Prospective study.

Procedure—Radiographs obtained via routine hip joint evaluations performed in sedated dogs of 10 popular breeds were randomly selected from a database. Measurements of distraction index (DI) and hipextended index (HEI) on 1 hip joint radiograph randomly chosen from each dog were made.

Results—Mean age of dogs was 20.7 months. Mean HEI was 0.17 (range, 0.0 to 0.72) and mean DI was 0.44 (range, 0.07 to 0.96). Borzois had uniformly tight hip joints as judged by use of both methods and were considered the gold standard by which hip joint laxity was judged (all Borzois had DI ≤ 0.32). Overall, DI was significantly greater than HEI. Within each breed, mean DI was always greater than mean HEI. Significant differences were detected among breeds for HEI; however, compared with DI, the magnitude of differences among breeds was less.

Conclusions and Clinical Relevance—Distraction radiography detected the greatest range and magnitude of passive hip laxity in the 10 breeds of dogs. The difference in values between breeds known to have high prevalence of canine hip dysplasia and those in Borzois was greater for DI than for HEI. Breeds must be evaluated individually because of inherent differences in hip joint laxity. ( J Am Vet Med Assoc 2004; 224:542–546)

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in Journal of the American Veterinary Medical Association