Search Results

Abstract

Objective—To measure and compare synovial fluid antibody titers to type-I and -II collagen in stifle joints with instability caused by complete or partial cranial cruciate ligament (CCL) rupture and joints with osteoarthrosis secondary to other pathologic changes in dogs.

Animals—82 dogs with diseased stifle joints.

Procedure—Synovial fluid samples were collected from 7 dogs with clinically normal stifles (control group) and 82 dogs with diseased joints (50 stifle joints with complete rupture of the CCL, 20 with partial damage of the CCL, and 12 joints with radiographic signs of osteoarthritis secondary to other arthropathies). Synovial fluid samples were tested for autoantibodies to type-I and -II collagen by an ELISA.

Results—In dogs with complete and partial CCL rupture, synovial fluid antibody titers to type-I and -II collagen were significantly increased, compared with control dogs. Forty-eight percent (24/50) of samples from dogs with complete CCL rupture and 35% (7/20) of samples from dogs with partial CCL rupture had antibody titers to type-I collagen that were greater than the mean plus 2 standard deviations of the control group titers. Synovial fluid antibody titers to type- II collagen were high in 40% of the dogs with partial or (8/20) complete (20/50) CCL rupture. Dogs with osteoarthrosis secondary to other pathologic changes had significantly increased synovial fluid antibodies to type-I and -II collagen, compared with control dogs.

Conclusion—Increases in autoantibodies to collagen in synovial fluid are not specific for the type of joint disorder. It is unlikely that the anticollagen antibodies play an active role in the initiation of weakening of the CCL. (Am J Vet Res 2000;61:1456–1461)

Abstract

Objective—To determine the in vitro structural and material properties of braided, multifilament, nonabsorbable polyester tapes, used for intra-articular stabilization of cranial cruciate ligament- (CCL-) deficient stifle joints in dogs, and compare those with properties of multifilament polyamide tapes.

Sample Population—30 polyester tapes (width, 4 mm), 10 polyester tapes (width, 7 mm), and 30 polyamide tapes (width, 4 mm) were tested to failure. Cyclic loading experiments were also performed, using 3 polyester tapes of each width.

Procedure—Tapes were mounted in a tensile tester as single loops, simulating intra-operative conditions, and elongated to failure at 1,000 mm/min. Additionally, the behavior of polyester tapes was tested at different elongation rates. In a second series of experiments, biomechanical variables of the polyester tapes were measured after 25 sets of 2,000 cycles between physiologic force limits.

Results—Mean (± SD) ultimate loads of the 4-mm wide polyamide tapes, 4-mm wide polyester tapes, and 7-mm wide polyester tapes were 266.48 ± 13.19 301.78 ± 16.92, and 726.40 ± 37.74 N, respectively. Corresponding stiffnesses were 15.57 ± 0.49, 21.63 ± 2.19, and 34.85 ± 2.66 N/mm, respectively. Failure properties of polyester tapes were affected by previous cyclic loading.

Conclusions and Clinical Relevance—Polyester tapes of 4- or 7-mm widths should be able to resist forces resulting from weight bearing in dogs, suggesting that these tapes will be effective for stabilization of the stifle joint in dogs with a ruptured CCL. ( Am J Vet Res 2001;62:48–53)

Abstract

Objective—To test a modified saline (0.9% NaCl) solution joint washing (lavage) technique that includes the use of vitamin B₁₂ as an internal marker for the evaluation of synovial fluid dilution in lavage samples from canine joints.

Sample Population—9 plasma samples obtained from blood samples of 9 healthy dogs and 9 synovial fluid samples aspirated from stifle joints of 9 cadaveric dogs.

Procedure—Photometric absorbances of 25% vitamin B₁₂ solution, canine synovial fluid, and canine plasma were measured in a spectrophotometer to establish an optimal wavelength for analysis. Canine synovial fluid and plasma samples were mixed with the 25% vitamin B₁₂ solution to obtain 1%, 3%, 5%, 10%, 20%, and 50% solutions of synovial fluid or plasma. Diluted synovial fluid and plasma samples were used to simulate joint lavage samples and to examine the possible interference of these substances (synovial fluid or plasma) with the absorbance of the 25% vitamin B₁₂ solution in photometric analysis.

Results—The optimal wavelength was found to be at 550 nm. Canine synovial fluid and plasma samples did not interfere with the absorbance measurements of the 25% vitamin B₁₂ solution up to a 50% dilution of plasma or synovial fluid.

Conclusions and Clinical Relevance—The modified saline solution joint lavage method with the use of a 25% vitamin B₁₂ solution as an internal standard provides an accurate and reliable technique for the evaluation of synovial fluid dilution in lavage samples from canine joints. (Am J Vet Res 2005;66:1903–1906)

Abstract

Objective—To provide a detailed anatomic description of the thorax in clinically normal dogs by means of computed tomography.

Animals—4 clinically normal adult German Shepherd Dogs weighing 28 to 37 kg.

Procedure—Dogs were anesthetized and positioned in ventral recumbency for computed tomographic (CT) examination of the thorax. A CT image from the thoracic inlet to the diaphragm was made by use of a third-generation scanner with a slice thickness of 5 mm. Individual images were reviewed by use of soft tissue (window width, 250 Hounsfield units; window level, 35 Hounsfield units) and lung (window width, 1,000 Hounsfield units; window level, –690 Hounsfield units) settings. One dog, weighing 28 kg, was euthanatized, bound on a wooden frame in the same position as used for CT examination, and frozen at –14oC until solid. By use of an electric band saw, the frozen thorax was sectioned at 10-mm-thick intervals. Slab sections were immediately cleaned, photographed, and compared with corresponding CT images.

Results—Anatomic sections were studied, and identified anatomic structures were matched with structures on corresponding CT images. Except for some blood vessels and details of the heart, most of the bony and soft tissue structures of the thorax discerned on anatomic slices could be found on matched CT images.

Conclusions and Clinical Relevance—Because CT images provide detailed information on most structures of the canine thorax, results of our study could be used as a guide for evaluation of CT images of the thorax of dogs with thoracic diseases. (Am J Vet Res 2005;66:512–524)

Abstract

Objective—To evaluate anticollagen type I antibodies in synovial fluid of the affected stifle joint, the contralateral stifle joint, and the left shoulder joint of dogs with unilateral cranial cruciate ligament (CrCL) rupture during an extended period of 12 to 18 months.

Animals—13 client-owned dogs with CrCL rupture and 2 sham-operated dogs.

Procedures—All dogs were examined and arthrocentesis of all 3 joints was performed every 6 months after surgery. Synovial fluid samples were tested for anticollagen type I antibodies by use of an ELISA.

Results—Dogs with partial CrCL rupture had higher antibody titers than dogs with complete rupture. Six of 13 dogs ruptured the contralateral CrCL during the study, whereby higher antibody titers were found for the stifle joints than for the shoulder joint. Seronegative dogs or dogs with extremely low antibody titers and 2 dogs with high antibody titers did not sustain a CrCL rupture in the contralateral stifle joint.

Conclusions and Clinical Relevance—In most dogs that had a CrCL rupture of the contralateral stifle joint, a distinct antibody titer gradient toward the stifle joints was detected, suggesting that there was a local inflammatory process in these joints. However, only a small number of sham-operated dogs were used to calculate the cutoff values used to determine the anticollagen type I antibody titers in these patients. Synovial fluid antibodies against collagen type I alone do not initiate CrCL rupture because not all dogs with high antibody titers sustained a CrCL rupture in the contralateral stifle joint.

Abstract

Objective—To examine mRNA expression of cytokines in synovial fluid (SF) cells from dogs with cranial cruciate ligament (CrCL) rupture and medial patellar luxation (MPL) and determine mRNA expression for 3 joints (affected stifle, unaffected contralateral stifle, and left shoulder joints) in dogs with unilateral CrCL rupture.

Sample Population—29 stifle joints with CrCL rupture (29 dogs), 8 stifle joints with MPL (7 dogs), and 24 normal stifle joints (16 clinically normal dogs).

Procedures—Immediately before reconstructive surgery, SF was aspirated from the cruciate-deficient stifle joint or stifle joint with MPL. Fourteen of 29 dogs had unilateral CrCL rupture; SF was also aspirated from the unaffected contralateral stifle joint and left shoulder joint. Those 14 dogs were examined 6 and 12 months after reconstructive surgery. Total RNA was extracted from SF cells and reverse transcription–PCR assay was performed to obtain cDNA. Canine-specific cytokine mRNA expression was determined by use of a real-time PCR assay.

Results—Interleukin (IL)-8 and -10 and interferon-G expression differed significantly between dogs with arthropathies and dogs with normal stifle joints. For the 14 dogs with unilateral CrCL rupture, a significant difference was found for IL-8 expression. Before reconstructive surgery, IL-8 expression differed significantly between the affected stifle joint and left shoulder joint or contralateral stifle joint. Six months after surgery, IL-8 expression was significantly increased in the unaffected contralateral stifle joint, compared with the shoulder joint.

Conclusions and Clinical Relevance—No conclusions can be made regarding the role of the examined cytokines in initiation of CrCL disease.

Abstract

Case Description—A 5.5-month-old female domestic longhair cat was examined because of dorsal deviation of the caudal aspect of the sternum and progressively worsening dyspnea during play activities.

Clinical Findings—A diagnosis of pectus excavatum was made clinically and confirmed radiographically. The cardiac silhouette was shifted into the right hemithorax. The vertebral index (VI) and frontosagittal index (FSI), which are radiographic indices used to grade the extent of the deformity, were 5.2 and 3.0, respectively. Minimum thoracic height was 13 mm at this time.

Treatment and Outcome—The sternal malposition was corrected during surgery; for stabilization, an internal splint was provided by use of a plate that was applied to the ventral side of the sternum. Radiographic indices improved until day 85; at that time, an increase in the distance between plate and sternum was detected, and plate removal was advised. The radiographic indices improved again after plate removal. At 310 days after surgery, VI was 9.6, FSI was 1.6, and minimum thoracic height was 34 mm. No dyspnea was evident during physical examination.

Clinical Relevance—Results of treatment suggest that this technique may be useful as an alternative surgical option for cats with pectus excavatum that have a noncompliant sternum.

Abstract

Objective—To provide a detailed anatomic description of brain structures in clinically normal dogs by means of computed tomography (CT).

Animals—4 clinically normal adult German Shepherd Dogs weighing 30 to 35 kg.

Procedure—Each dog was anesthetized and positioned in ventral recumbency for CT examination of the brain; transverse scans were completed at 2-mm intervals from the cribriform plate of the ethmoid bone to the cranial part of the atlas by use of a thirdgeneration CT scanner. Contrast material was injected IV, and a second series of scans was completed. Images (with or without contrast) from all dogs were reviewed by use of a soft tissue setting (window width, 150 Hounsfield units; window level, 50 Hounsfield units). One of the dogs was euthanatized, and a 3.5% formaldehyde solution was perfused via the common carotid arteries. After fixation, the brain was embedded in gelatin and sectioned into 5-mm thick transverse sections by use of a stainless-steel knife. Anatomic sections were photographed and compared with the corresponding CT views.

Results—Most features of the brain that were identified on anatomic sections could be identified on the corresponding CT scans despite the low contrast between structures, particularly if adjacent bony and soft tissue structures were used as landmarks. Additional anatomic structures surrounding the brain were also identifiable on the CT images.

Conclusions and Clinical Relevance—Images obtained in this study could be used as a guide for evaluation of CT images of the brain in dogs with brain diseases. (Am J Vet Res 2005;66;1743–1756)

Abstract

Objective—To obtain a detailed anatomic description of the rabbit head by means of computed tomography (CT).

Animals—6 clinically normal Dendermonde White rabbits weighing 3 kg and raised for human consumption and 1 Netherland dwarf rabbit.

Procedures—The commercially raised rabbits were slaughtered in a slaughterhouse, flayed, and decapitated. The dwarf rabbit was euthanatized. Two hours later, each rabbit head was positioned with the ventral side on the CT table to obtain transverse and sagittal, 1-mm-thick slices. Dorsal images were obtained by placing each head perpendicular to the table. Immediately after the CT examination, 3 heads were frozen in an ice cube at −14°C until solid and then sectioned at 4-mm-thick intervals by use of an electric band saw. Slab sections were immediately cleaned, photographed, and compared with corresponding CT images. Anatomic sections were examined, and identified anatomic structures were matched with structures on corresponding CT images.

Results—The bone-window CT images yielded good anatomic detail of the dentition and the bony structures of rabbit skulls. The soft tissue structures that could be determined were not better identifiable on the soft tissue–window CT images than on the bone-window images.

Conclusions and Clinical Relevance—CT images of the heads of healthy rabbits yielded detailed information on the skull and some surrounding soft tissue structures. Results of this study could be used as a guide for evaluation of CT images of rabbits with various cranial and dental disorders.

Abstract

Objective—To assess the agreement between CT and MRI for enabling detection of intracranial lesions in cats and dogs.

Design—Evaluation study.

Animals—51 dogs and 7 cats with suspected intracranial lesions.

Procedures—During a 2-year-period, dogs and cats with suspected intracranial pathological changes underwent MRI and CT (single slice) of the head. Radiologists evaluated images produced with both techniques without awareness of subject identity. Agreement between methods was assessed for allowing detection of solitary or multiple lesions, selected lesion characteristics (via the Cohen κ statistic), and lesion dimensions (via Bland-Altman plots).

Results—CT and MRI had substantial agreement for allowing detection of lesions and identification of whether the lesions were solitary or multiple. The techniques agreed almost perfectly for allowing identification of a mass effect and contrast medium enhancement, which were considered principal diagnostic imaging signs. A lower degree of agreement was attained for allowing identification of enhancement patterns and aspects of lesion margins. Agreement was substantial to almost perfect for lesion visualization in most anatomic brain regions but poor for identification of lesion dimensions.

Conclusions and Clinical Relevance—Degrees of agreement between CT and MRI for allowing the detection and characterization of intracranial lesions ranged from poor to almost perfect, depending on the variable assessed. More investigation is needed into the relative analytic sensitivity and possible complementarities of CT and MRI in the detection of suspected intracranial lesions in dogs and cats.