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  • Author or Editor: Rory J. Todhunter x
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Abstract

Objective—To identify hemostatic imbalances indicative of an increased risk of intra-abdominal adhesion formation in foals versus adult horses.

Animals—Horses with colic undergoing exploratory laparotomy or abdominocentesis as part of a clinical examination (n = 16 foals ≤ 6 months of age and 19 adults ≥ 5 years of age) and horses without colic undergoing herniorrhaphy (15 foals) or euthanasia for noninflammatory and nongastrointestinal disease (10 foals and 20 adults).

Procedures—Paired abdominal fluid and blood samples were collected from each horse into buffered sodium citrate and centrifuged immediately after collection. Supernatants were stored at −80°C, then thawed for measurement of fibrinogen concentration, plasminogen activity, antiplasmin activity, and D-dimer concentration. Supernatant analyte concentrations or activities were compared within age group (foals with and without colic vs adults with and without colic) and within disease status (foals and adults without colic vs foals and adults with colic).

Results—All analyte concentrations or activities in abdominal fluid samples were significantly lower in the noncolic groups than in the colic groups, and none differed between foal and adult groups. Several plasma analyte values differed by disease status and age.

Conclusions and Clinical Relevance—The risk of intra-abdominal adhesion formation in the foals in this study did not appear to be attributable to differences in intra-abdominal hemostasis between adult horses and foals. Strategies for initial medical and surgical management of colic in adult horses may be applicable to foals with similar disorders.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To compare the trotting gaits of Labrador Retrievers and Greyhounds to determine whether differences in locomotion are attributable to differences in their manner of moving or to body size and shape differences between these 2 breeds.

Animals—8 healthy 5-month-old Greyhounds and 5 healthy Labrador Retrievers between 6 and 18 months old.

Procedure—A series of 4 force platforms was used to record independent ground reaction forces on the forelimbs and hind limbs during trotting. Values of stride parameters were compared between breeds before and after normalization for size differences. Standard values of absolute and normalized stride period and stride length were determined from linear regressions of these parameters on relative (normalized) velocity. Forces were normalized to body weight and compared at the same relative velocity.

Results—Greyhounds used fewer, longer strides than the Labrador Retrievers to travel at the same absolute speed. After normalization for body size differences, most measurable differences between breeds were eliminated. Subtle differences that did persist related to proportion of the stride that the forefoot was in contact with the ground, timing of initial hind foot contact relative to initial forefoot contact, and distribution of vertical force between the forelimbs and hind limbs.

Conclusions and Clinical Relevance—Results suggest that apparent differences in the trotting gait between Labrador Retrievers and Greyhounds are mainly attributable to differences in size, and that dogs of these 2 breeds move in a dynamically similar manner at the trot. (Am J Vet Res 2000;61: 832–838)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine the effect of nonthermal plasma on Staphylococcus aureus, fibroblasts in monolayer culture, and clean and contaminated skin explants.

Sample Population—Normal skin from euthanized horses.

ProceduresS aureus organisms were plated and treated with nonthermal plasma followed by bacterial culture to assess viability. Fibroblasts in monolayer culture and the epidermal and dermal surfaces of clean and S aureus–contaminated skin explants were treated. The effects of distance and duration on the response to treatment were compared.

Results—Compared with controls, treatment with nonthermal plasma resulted in significantly decreased bacterial growth and significantly inhibited survival of fibroblasts in monolayer culture. When epidermal and dermal surfaces of skin explants were treated, there was no effect on production of normal fibroblasts during explant culture, except when extended exposure times of ≥ 2 minutes were used. Treatment with nonthermal plasma resulted in significantly lower bacterial counts after 24 hours of culture of S aureus–contaminated epidermis but not of dermis.

Conclusions and Clinical Relevance—Nonthermal plasma resulted in bacterial decontamination of agar and epithelium; negative effects on fibroblasts in monolayer; and no negative effects on skin explants, except at long exposure times. Use of nonthermal plasma appears safe for treatment of epithelialized surfaces, may be safe for granulating wounds, and results in decontamination of S aureus. Investigations on the effects that nonthermal plasma may have on patient tissues are indicated with a clinically applicable delivery device.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate the quantitative inheritance of secondary hip joint osteoarthritis in a canine pedigree.

Animals—137 Labrador Retrievers, Greyhounds, and mixed-breed dogs.

Procedures—Necropsy scores ranging from 0 to 4 were obtained for each hip joint. Seven unaffected Greyhounds with normal hip joint conformation were also used for genetic modeling, but were not euthanized. Sixty-six male and 71 female dogs were allocated to 2 groups (≤ 12 months of age and > 12 months of age). Statistical models were developed to establish the inheritance pattern of hip joint osteoarthritis that developed secondary to hip dysplasia.

Results—62 dogs had evidence of osteoarthritis in a hip joint, and 75 had no evidence of osteoarthritis. After sex was adjusted for, the necropsy score was found to be inherited additively but without dominance. Each Labrador Retriever allele increased the necropsy score by 0.7 to 0.9 points, compared with the Greyhound allele, and male sex increased the necropsy score 0.74 over female sex. Approximately 10% of the variation in necropsy score was attributable to the litter of puppies' origin.

Conclusions and Clinical Relevance—Because secondary hip joint osteoarthritis is inherited additively, selection pressure could be applied to reduce its incidence. Similar statistical models can be used in linkage and association mapping to detect the genes in the underlying quantitative trait loci that contribute to hip joint osteoarthritis.

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE To identify risk factors associated with surgical site infection (SSI) in dogs following tibial plateau leveling osteotomy (TPLO).

DESIGN Retrospective cohort study.

ANIMALS 320 dogs that underwent unilateral or bilateral TPLO (n = 405 procedures) between 2007 and 2015 and were reexamined by a veterinarian at least once ≥ 8 weeks after the procedure.

PROCEDURES Data were extracted from medical records regarding signalment, TPLO procedure details, medical history of dermatitis, and SSI status. Logistic regression was performed to identify factors associated with SSI development.

RESULTS An SSI developed following 34 (8.4%; 95% confidence interval [CI], 6.1% to 11.5%) procedures. Prophylactic antimicrobial administration was provided following 36.8% (n = 149) of procedures. For 71 (17.5%) procedures, the dog had dermatitis at the time of surgery; 12 of these procedures involved dermatitis at the surgical site. The incidence of SSI following the 12 procedures for dogs with dermatitis at the surgical site was 16.7% (2/12 [95% CI, 3.3% to 54.3%]) and was 10.2% (6/59 [95% CI, 4.5% to 21.3%]) for dogs with dermatitis elsewhere; however, these differences in incidence were not significant. On multivariable analysis, German Shepherd Dogs (vs other breeds), meniscectomy (vs no meniscectomy), and attending surgeon having performed ≤ 20 (vs > 20) procedures during the study period were associated with increased odds of SSI.

CONCLUSIONS AND CLINICAL RELEVANCE SSI following TPLO was associated with the German Shepherd breed, meniscectomy, and surgeon. Prospective studies are needed to investigate the mechanisms underlying these associations.

Restricted access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To compare the bone mineral density (BMD) of the proximal portion of the femur in dogs with and without early osteoarthritis secondary to hip dysplasia.

Animals—24 dogs (3 Greyhounds, 6 Labrador-Greyhound crossbreeds, and 15 Labrador Retrievers).

Procedure—Computed tomography (CT) of the pelvis, including a bone-density phantom, was performed for each dog. Centrally located transverse CT slices and a computer workstation were used to identify 16 regions of interest (ROIs) in the proximal portion of the femur. For each ROI, the mean Hounsfield unit value was recorded; by use of the bone-density phantom and linear regression analysis, those values were converted to equivalent BMD (eBMD). Mean eBMD values for the subchondral and nonsubchondral ROIs in dogs with and without osteoarthritis (determined at necropsy) were compared. A mixed-model ANOVA and post hoc linear contrasts were used to evaluate the effects of osteoarthritis, breed, and sex on the BMD value.

Results—At necropsy, osteoarthritis was detected in 14 hip joints in 9 dogs; all lesions included early cartilage fibrillation. After adjusting for breed and sex, eBMD in subchondral ROIs 8 and 12 (adjacent to the fovea) were 8% and 6% higher, respectively, in osteoarthritis-affected dogs, compared with unaffected dogs; in the nonsubchondral ROIs, eBMD was 10% higher in osteoarthritis-affected dogs.

Conclusions and Clinical Relevance—Compared with findings in unaffected dogs, increased eBMD in hip joints of dogs with early osteoarthritis supports a strong relationship between the subchondral and epiphyseal regions and articular cartilage in the pathogenesis and progression of osteoarthritis.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To compare the accuracy of the extended- hip radiographic (EHR) score, the distraction index (DI), and the dorsolateral subluxation (DLS) score for identifying hip dysplasia in dogs at 8 months of age.

Design—Cohort study

Animals—129 Labrador Retrievers, Greyhounds, and Labrador Retriever-Greyhound crossbreds.

Procedure—Radiography was performed when dogs were 8 months of age. Dogs were euthanatized at 8 to 36 months of age; hip dysplasia was diagnosed at the time of necropsy on the basis of results of a gross examination of the articular cartilage of the hip joints for signs of osteoarthritis.

Results—The EHR score, DI, and DLS score at 8 months of age were all significantly correlated with degree of cartilage degeneration at necropsy. Sensitivity and specificity of using EHR score at 8 months of age to diagnose hip dysplasia (scores > 3 were considered abnormal) were 38 and 96%, respectively; sensitivity and specificity of using DI (values > 0.7 were considered abnormal) were 50 and 89%; and sensitivity and specificity of using DLS score (scores ≤ 55% were considered abnormal) were 83 and 84%.

Conclusions and Clinical Relevance—Results suggested that specificities of the 3 methods for diagnosing hip dysplasia in dogs at 8 months of age were similar. However, the DLS score had higher sensitivity, indicating that there were fewer false-negative results. (J Am Vet Med Assoc 2001;219:1242–1246)

Restricted access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine whether dorsolateral subluxation (DLS) scores in young dogs could be used to reliably predict which dogs would develop evidence of hip osteoarthritis and whether DLS scores measured at various ages correlated with each other.

Animals—129 Labrador Retrievers, Greyhounds, and Labrador Retriever-Greyhound crossbreds.

Procedures—DLS scores were measured on radiographs taken at 4, 8, and 12 months of age and at necropsy (8 to 36 months of age). At necropsy, the hip joints were examined macroscopically and a score assigned for degree of cartilage degeneration.

Results—DLS scores at 4 (n = 35, r s = –0.62), 8 (n = 106, r s = –0.54), and 12 (n = 15, r s = –0.87) months of age were significantly correlated with cartilage degeneration scores, and DLS scores at 8 months of age were significantly correlated with scores obtained at the time of necropsy (n = 39, r s = 0.87). The DLS scores at 4 months of age were significantly different from scores at 8 months of age, but scores did not differ significantly thereafter. Likelihood ratios for cartilage lesions for low (< 45%), intermediate (≥ 45 but ≤ 55%), and high (> 55%) DLS scores at 8 months of age were 8.0, 2.6, and 0.2, respectively.

Conclusions and Clinical Relevance—Results suggest that DLS score at 8 months of age was a reasonable, albeit imperfect, predictor of the condition of the hip joint cartilage at necropsy. Thus, the DLS method might be useful for early identification of dogs with hip dysplasia. (Am J Vet Res 2001;62:1711–1715)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate the quality of information regarding osteoarthritis (OA) in dogs currently available on the World Wide Web.

Design—Survey study.

Procedure—5 search engines were searched with the keywords "dog," "degenerative joint disease," "canine," and "osteoarthritis," and the first 50 sites listed by each search engine were analyzed. Unique Web site addresses were distributed to 3 diplomates of the American College of Veterinary Surgeons, who provided a standardized evaluation of each site.

Results—30 unique Web sites were evaluated. Twenty (66%) provided information consistent with conventional knowledge as outlined in textbooks and peer-reviewed literature, 8 (27%) provided experimental or anecdotal information in addition to conventional knowledge, and 2 (7%) provided misleading information. Mean scores for overall usefulness of the information provided in regard to clinical features of and treatment for OA were 1.3 and 1.5, respectively (1 = information of minimal use; 5 = very useful information). Twenty-three (77%) sites encouraged pet owners to seek the advice of a veterinarian. Twenty-three (77%) sites were given overall quality scores < 2, and 7 (23%) were given scores between 2 and 3 (1 = site was counterproductive; 5 = site was very valuable).

Conclusions and Clinical Relevance—Results suggest that the quality of information currently available on the Web that addresses OA in dogs is questionable. Although most of the sites conveyed some conventional information with reasonable accuracy, the information was incomplete, of minimal use, and often considered counterproductive. (J Am Vet Med Assoc 2003;223:1272–1275)

Restricted access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To analyze a centrifugation-based, point-of-care device that concentrates canine platelets and bone marrow–derived cells.

Animals—19 adult sexually intact dogs.

Procedures—Anticoagulated peripheral blood (60 mL) and 60 mL of anticoagulated bone marrow aspirate (BMA) were concentrated by centrifugation with the centrifugation-based, point-of-care device to form a platelet and a bone marrow concentrate (BMC) from 11 dogs. Blood samples were analyzed on the basis of hemograms, platelet count, and PCV. The BMA and BMC were analyzed to determine PCV, total nucleated cell count, RBC count, and differential cell counts. The BMC stromal cells were cultured in an osteoinductive medium. Eight additional dogs were used to compare the BMC yield with that in which heparin was infused into the bone marrow before aspiration.

Results—The centrifugation-based, point-of-care device concentrated platelets by 6-fold over baseline (median recovery, 63.1%) with a median of 1,336 × 103 platelets/μL in the 7-mL concentrate. The nucleated cells in BMCs increased 7-fold (median recovery, 42.9%) with a median of 720 × 103 cells/μL in the 4-mL concentrate. The myeloid nucleated cells and mononuclear cells increased significantly in BMCs with a significant decrease in PCV, compared with that of BMAs. Stromal cell cultures expressed an osteoblastic phenotype in culture. Infusion of heparin into the bone marrow eliminated clot formation and created less variation in the yield (median recovery, 61.9%).

Conclusions and Clinical Relevance—Bone marrow–derived cell and platelet-rich concentrates may form bone if delivered in an engineered graft, thus decreasing the need for cancellous bone grafts.

Full access
in American Journal of Veterinary Research