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- Author or Editor: André Busato x
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Objective—To evaluate the possible association between facet joint geometry and intervertebral disk degeneration in German Shepherd Dogs.
Animals—25 German Shepherd Dogs and 11 control dogs of similar body weight and condition.
Procedure—Facet joint angles in the caudal portion of the lumbar region of the vertebral column (L5-S1) were measured by use of computed tomography, and the intervertebral discs were evaluated microscopically. The relationship between facet joint geometry and disk degeneration was evaluated by use of statistical methods.
Results—German Shepherd Dogs had significantly more facet joint tropism than control dogs, but an association with disk degeneration was not found. However, German Shepherd Dogs had a different facet joint conformation, with more sagittally oriented facet joints at L5-L6 and L6-L7 and a larger angle difference between the lumbar and lumbosacral facet joints, compared with control dogs.
Conclusion and Clinical Relevance—A large difference between facet joint angles at L6-L7 and L7-S1 in German Shepherd Dogs may be associated with the frequent occurrence of lumbosacral disk degeneration in this breed. (Am J Vet Res 2002;63:86f–90)
Objective—To measure concentrations of nitric oxide metabolites (nitrite-nitrate [NOt]) in cartilage, synovial membrane, and cranial cruciate ligament (CCL) in dogs and evaluate associations with osteoarthritis in dogs with CCL rupture.
Animals—46 dogs with CCL rupture and 54 control dogs without joint disease.
Procedure—Tissue specimens for histologic examination and explant culture were harvested during surgery in the CCL group or immediately after euthanasia in the control group; NOt concentrations were measured in supernatant of explant cultures and compared among dogs with various degrees of osteoarthritis and between dogs with and without CCL rupture.
Results—Osteoarthritic cartilage had significantly higher NOt concentration (1,171.6 nmol/g) than did healthy cartilage (491.0 nmol/g); NOt concentration was associated with severity of macroscopic and microscopic lesions. Synovial membrane NOt concentration did not differ between dogs with and without CCL rupture. Ruptured CCL produced less NOt than did intact ligaments. In control dogs, NOt concentrations were similar for intact ligaments (568.1 nmol/g) and articular cartilage (491.0 nmol/g). Synthesis of NOt was inhibited substantially by coincubation with inhibitors.
Conclusions and Clinical Relevance—Results suggest that NOt in canine joint tissues originates from the inducible nitric oxide synthase pathway. Nitric oxide metabolite production in cartilage was greater in dogs with osteoarthritis than in healthy dogs and was associated with lesion severity, suggesting that nitric oxide inhibitors may be considered as a treatment for osteoarthritis. The CCL produces substantial concentrations of NOt; the importance of this finding is unknown. ( Am J Vet Res 2000;61:530–536)
Objective—To estimate genetic population variables for 6 radiographic criteria of canine hip dysplasia (CHD).
Animals—664 full- and half-siblings from a colony of Labrador Retrievers.
Procedure—Heritability estimates and genetic correlations were calculated for 6 radiographic criteria of CHD. Two evaluation protocols were compared: the grade of the most severely affected hip joint and the sum of the scores for both hip joints. The predictive performance of estimated breeding values was also evaluated.
Results—The overall prevalence of CHD (Fédération Cynologique Internationale grades C, D, and E) was 29.6%. Median age at radiographic examination was 377 days. Heritability for the total CHD grade, Norberg angle (NA), coverage of the femoral head (COV), craniodorsal acetabular rim (ACR), subchondral bone sclerosis (SUBCH), shape of the femoral head and neck (FHN), and osteoarthritic changes at the insertion site of the joint capsule (JC) was estimated as follows: 0.44, 0.43, 0.46, 0.37, 0.32, 0.21, and 0.05, respectively. Heritability estimates were slightly higher for the sum of the scores for both hip joints. If NA and COV were included as fixed effects in the model for the dependent variables ACR, SUBCH, FHN, and JC , then heritability of these traits significantly decreased (0.08 to 0.15). High scores of NA and COV lead to a significant increase of the scores of the remaining criteria.
Conclusions and Clinical Relevance—Canine hip dysplasia is heritable to a moderate degree. Signs of subluxation revealed the highest heritability estimates. The criteria ACR, SUBCH, FHN, and JC were strongly influenced by NA and COV. (Am J Vet Res 2001;62:846–852)
Objective—To investigate whether volumetric capnography indices could be used to differentiate between horses without recurrent airway obstruction (RAO) and horses with RAO that were in clinical remission or that had clinically apparent RAO.
Animals—70 adult Swiss Warmblood horses (20 used for pleasure riding and 50 used for dressage or show jumping).
Procedure—Horses were allocated to 4 groups on the basis of history, clinical signs, results of endoscopy, and cytologic findings (group 1, 21 healthy horses; group 2, 22 horses with RAO that were in remission; group 3, 16 horses with mild RAO; group 4, 11 horses with exacerbated RAO). Expiratory volume and CO2 curves were recorded by use of a computerized ultrasonic spirometer. Volumetric capnograms were plotted, and derived indices were calculated.
Results—Dead-space volume (VD) was calculated by use of the Bohr equation (VDBohr) and for physiologic VD (VDphys). Ratios for VDBohr to expiratory tidal volume (VT) and VDphys to VT as well as an index of effective CO2 elimination were significantly different among groups of horses. Age and use of the horses also significantly affected volumetric capnography indices.
Conclusions and Clinical Relevance—Ratios of VDBohr to VT and VDphys to VT as well as an index of effective CO2 elimination were sufficiently sensitive measures to distinguish between healthy horses and horses with RAO in remission. To optimize the ability of volumetric capnography indices to differentiate among horses in heterogeneous populations, it is important to account for effects of age and specific use of the horses. (Am J Vet Res 2003;64:338–345)
Objective—To characterize the mucosal IgE network in dogs affected with inflammatory bowel disease (IBD) and compare it with that for healthy dogs.
Animals—9 healthy dogs and 20 dogs with IBD.
Procedure—In situ hybridization of mRNA specific for IgE and interleukin 4 (IL-4) and immunohistochemical analysis for IgE protein and 2 markers of mast cells (ie, tryptase and chymase) were performed on tissue sections obtained from the gastrointestinal (GI) tract and lymph nodes of dogs.
Results—Dogs with IBD had significantly more cells positive for IgE protein and more mast cells in the GI mucosa than healthy dogs. Despite this significant increase in number of cells positive for IgE, cells positive for IgE mRNA were rarely detected in the GI mucosa; most cells positive for IgE mRNA were found in mesenteric lymph nodes. Signal pattern of IL-4 mRNA was similar to that of IgE mRNA.
Conclusions and Clinical Relevance—The increased numbers of cells positive for IgE and mast cells in dogs with IBD suggest hypersensitivity such as hypersensitivity to bacterial or dietary-derived antigens in the intestinal lumen. Future studies need to elucidate whether this represents a cause of inflammation or is a result of the inflammatory process of IBD. (Am J Vet Res 2001;62:211–216)
Objective—To determine the association between the 3-dimensional (3-D) motion pattern of the caudal lumbar and lumbosacral portions of the canine vertebral column and the morphology of vertebrae, facet joints, and intervertebral disks.
Sample Population—Vertebral columns of 9 German Shepherd Dogs and 16 dogs of other breeds with similar body weights and body conditions.
Procedure—Different morphometric parameters of the vertebral column were assessed by computed tomography (CT) and magnetic resonance imaging. Anatomic conformation and the 3-D motion pattern were compared, and correlation coefficients were calculated.
Results—Total range of motion for flexion and extension was mainly associated with the facet joint angle, the facet joint angle difference between levels of the vertebral column in the transverse plane on CT images, disk height, and lever arm length.
Conclusions and Clinical Relevance—Motion is a complex process that is influenced by the entire 3-D conformation of the lumbar portion of the vertebral column. In vivo dynamic measurements of the 3-D motion pattern of the lumbar and lumbosacral portions of the vertebral column will be necessary to further assess biomechanics that could lead to disk degeneration in dogs.
Objective—To evaluate the 3-dimensional motion pattern including main and coupled motions of the caudal lumbar and lumbosacral portions of the vertebral column of dogs.
Animals—Vertebral columns of 9 German Shepherd Dogs (GSDs) and 16 dogs of other breeds with similar body weights and body conditions .
Procedure—Main and coupled motions of the caudal lumbar and lumbosacral portions of the vertebral column (L4 to S1) were determined by use of a testing apparatus that permitted precise application of known pure moments to the vertebral column. Motion was compared between GSDs and dogs of other breeds.
Results—All specimens had a similar motion pattern consisting of main motion and a certain amount of coupled motion including translation. Vertebral columns of GSDs had significantly less main motion in all directions than that of dogs of other breeds. Translation was similar in GSDs and dogs of other breeds and was smallest at the lumbosacral motion segment.
Conclusions and Clinical Relevance—Results indicated that motion in the caudal lumbar and lumbosacral portions of the vertebral column of dogs is complex and provided a basis for further studies evaluating abnormal vertebral columns. ( Am J Vet Res 2004;65:544–552)