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in Journal of the American Veterinary Medical Association
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A 5-year-old male Labrador Retriever weighing 29.1 kg (64 lb) was referred to the University of Missouri Veterinary Medical Teaching Hospital for evaluation of lameness of the right forelimb. The dog was used for hunting purposes but was also considered a family pet. The owner reported a slight decrease in duration and quality of the dog's athletic performance over the past year, with a definite lameness beginning approximately 6 weeks before the referral, after the dog had jumped down into a stream while hunting. Physical and orthopedic examinations revealed the dog was in good body condition (score of 5

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in Journal of the American Veterinary Medical Association
Problem

A 4-year-old male German Shepherd Dog weighing 33.2 kg (73 lb) was evaluated at the University of Missouri Veterinary Medical Teaching Hospital for a 3-month history of decreased ability to perform athletically. The dog trained for and competed in agility events, and the owner had observed that the dog would refuse or not successfully complete jumps and A-frames during training and competition. According to the owner, the dog also had signs of mild, intermittent lameness of the right hind limb. When the owner first noticed the problem, the dog was evaluated by a veterinarian who diagnosed a possible hamstring

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in Journal of the American Veterinary Medical Association

A 2-year-old neutered male mixed-breed dog was evaluated for lameness with an abnormal, short-strided gait of the left hind limb of unknown duration. Physical examination revealed laxity and crepitus on palpation of the right hip joint, relative prominence of the left greater trochanter, and a bony mass-like effect on palpation of the left thigh. The left hip joint had limited range of motion (approx 40°) and crepitus and abnormal fulcrum action of the limb during flexion and extension. Routine bloodwork (CBC and serum biochemical analyses) had been performed 5 days prior to referral and did not reveal substantial abnormalities. Lateral

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the quantity (concentration) and quality (molecular weight) of synovial fluid hyaluronan with respect to presence and severity of osteoarthritis in stifle joints of dogs.

Animals—21 purpose-bred dogs and 6 clinically affected large-breed dogs (cranial cruciate ligament [CrCL] disease with secondary osteoarthritis).

Procedures—Research dogs underwent arthroscopic surgery in 1 stifle joint to induce osteoarthritis via CrCL transection (CrCLt; n = 5 stifle joints), femoral condylar articular cartilage groove creation (GR; 6), or meniscal release (MR; 5); 5 had sham surgery (SH) performed. Contralateral stifle joints (n = 21) were used as unoperated control joints. Synovial fluid was obtained from research dogs at time 0 and 12 weeks after surgery and from clinically affected dogs prior to surgery. All dogs were assessed for lameness, radiographic signs of osteoarthritis, and pathologic findings on arthroscopy as well as for quantity and quality of hyaluronan.

Results—Clinically affected dogs had significantly greater degrees of pathologic findings, compared with dogs with surgically induced osteoarthritis (ie, those with CrCLt, GR, and MR stifle joints), and with respect to lameness scores, radiographic signs of osteoarthritis, pathologic findings on arthroscopy, and synovial fluid hyaluronan concentration. Synovial fluid from stifle joints of dogs with surgically induced osteoarthritis had hyaluronan bands at 35 kd on western blots that synovial fluid from SH and clinically affected stifle joints did not.

Conclusions and Clinical Relevance—Synovial fluid hyaluronan quantity and quality were altered in stifle joints of dogs with osteoarthritis, compared with control stifle joints. A specific hyaluronan protein fragment may be associated with early pathologic changes in affected joints.

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

Abstract

Objective—To determine the effects of interleukin (IL)-1β on matrix synthesis and degradation by chondrocytes cultured in a 3-dimensional (3-D) gel medium.

Sample Population—Chondrocytes from 7 dogs.

Procedure—Articular chondrocytes were harvested and cultured in 3-D gel medium alone or with 10 or 20 ng IL-1βml that was added beginning on day 0, 3, 6, or 9. On days 3, 6, 12, and 20 of 3-D culture, samples of the liquid medium were evaluated for glycosaminoglycan (GAG), prostaglandin E2 (PGE2), and matrix metalloprotease (MMP)-3 content. The 3-D plug in each well was evaluated for histologic characteristics of viability, cell morphology, and proteoglycan staining, immunohistochemically stained for collagen type II, and spectrophotometrically analyzed for GAG content.

Results—Significant differences for all variables were detected between controls and each IL-1β group, among groups with different IL-1β concentrations, and among groups with IL-1β added at various time points. Chondrocytes exposed to IL-1β had loss of GAG, increased PGE2 and MMP-3 concentrations, and lack of collagen type-II synthesis. These IL-1β effects appeared to be time and concentration dependent.

Conclusions—Addition of IL-1β to chondrocytes in 3- D gel medium results in time- and concentrationdependent effects on matrix synthesis and degradation and provides an appropriate in vitro model for many of the pathophysiologic events associated with osteoarthritis. (Am J Vet Res 2000;61:766–770)

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in American Journal of Veterinary Research

Abstract

Objective—To characterize chondrocytes from naturally occurring osteochondrosis (OC) lesions of the humeral head of dogs.

Sample Population—15 cartilage specimens from 13 client-owned dogs with humeral head OC and 10 specimens from the humeral head of healthy dogs (controls).

Procedure—Chondrocytes were isolated and cultured in a 3-dimensional system. On days 7, 10, 15, 20, and 25, glycosaminoglycan and hydroxyproline content and cytologic characteristics were evaluated. Expression of collagen types I, II, and X was assessed by use of immunohistochemistry.

Results—Chondrocytes from OC lesions were less viable, compared with control chondrocytes. Glycosaminoglycan content in the OC group was significantly less than in the control group on all days except day 20. Hydroxyproline content was also significantly less in the OC group on days 10, 20, and 25. Expression of collagen type II was significantly less in the OC group, compared with the control group on all days, whereas expression of collagen type I was significantly greater in the OC group on days 20 and 25. Expression of collagen type X was significantly less in the OC group on all days except day 25.

Conclusions and Clinical Relevance—Chondrocytes from naturally occurring OC lesions of the humeral head of dogs cultured in a 3-dimensional system were less viable and less capable of producing appropriate extracellular matrix molecules than chondrocytes from unaffected dogs. Alterations in the synthetic capabilities of chondrocytes from OC-affected cartilage may be a cause or an effect of the disease process. (Am J Vet Res 2002;63:186–193)

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in American Journal of Veterinary Research
Problem

A 6-year-old spayed female Newfoundland weighing 57.5 kg (126.5 lb) was evaluated at the University of Missouri Veterinary Medical Teaching Hospital for a 5-month history of right hind limb lameness manifested as a decrease in physical activity difficulty rising from a recumbent position, and disinterest in swimming, one of the dog's preferred activities before the lameness developed. The dog was a household pet that lived indoors and was allowed to roam freely on the owners' farm. The owners initially sought advice from their local veterinarian who had sequentially prescribed 2 types of NSAIDs; the owners reported minimal improvement with

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