A retrospective study of 40 dogs with polyarthritis.

peer reviewedOBJECTIVE: To characterize the epidemiologic, clinical, laboratory, and radiographic findings from dogs with polyarthritis (PA). STUDY DESIGN: Retrospective clinical study. SAMPLE POPULATION: Forty dogs. METHODS: Medical records of 40 dogs with a diagnosis of PA were reviewed. Retrieved data included breed, age at admission, sex, weight, clinical signs, and the results of synovial fluid analysis, complete blood count, serum chemistry profile, urinalysis, serologic screening tests for infectious diseases, and radiographic examination of affected joints. RESULTS: The incidence of PA was 0.37%. Twenty-nine breeds were represented; 16 dogs were male, and 24 were female. Mean body weight was 20.1 +/- 15 kg. The mean age at admission was 5.6 +/- 4 years. Eighty percent of dogs with PA had difficulty or reluctance walking, 35% were lame, 33% had spontaneous vocalization without any obvious reason, 20% had exercise intolerance, 18% were febrile, and 7.5% had an inability to rise or move. Joint pain was identified in 40% of dogs. Synovial fluid color varied from colorless (36%) to yellow-tinged (36%) or hemorrhagic (28%). Synovial fluid mean cell count varied from 10 cells (400x) to 50 cells (1,000x). Leukocytosis occurred in 59% of the dogs and was more frequently identified in dogs with very severe synovial inflammation. Thirty-one percent of affected dogs were anemic. Serum biochemical profiles were considered abnormal in 13% of the dogs. Joint radiography did not identify erosive arthritis. CONCLUSIONS: PA is a common cause of locomotor abnormalities in dogs; however, true lameness and articular pain are not common clinical findings in dogs with PA. CLINICAL RELEVANCE: PA should be considered in the differential diagnosis for all dogs with difficulty walking

Anatomic study of the canine stifle using low-field magnetic resonance imaging (MRI) and MRI arthrography

Objective: To investigate the use of low-field magnetic resonance imaging (MRI) and MR arthrography in normal canine stifles and to compare MRI images to gross dissection. Study Design: Descriptive study. Sample Population: Adult canine pelvic limbs (n=17). Methods: Stifle joints from 12 dogs were examined by orthopedic and radiographic examination, synovial fluid analysis, and MRI performed using a 0.2 T system. Limbs 1 to 7 were used to develop the MR and MR arthrography imaging protocol. Limbs 8-17 were studied with the developed MR and MR arthrography protocol and by gross dissection. Three sequences were obtained: T1-weighted spin echo (SE) in sagittal, dorsal, and transverse plane; T2-weighted SE in sagittal plane and T1-gradient echo in sagittal plane. Results: Specific bony and soft tissue structures were easily identifiable with the exception of articular cartilage. The cranial and caudal cruciate ligaments were identified. Medial and lateral menisci were seen as wedge-shaped hypointense areas. MR arthrography permitted further delineation of specific structures. MR images corresponded with gross dissection morphology. Conclusions: With the exception of poor delineation of articular cartilage, a low-field MRI and MR arthrography protocol provides images of adequate quality to assess the normal canine stifle joint