Resolution of reactive arthritis after splenectomy in a dog with a nonneoplastic splenic hyperplastic nodule.

CASE DESCRIPTION: A 10-year-old spayed female Golden Retriever was examined because of a 3-month history of lethargy, anorexia, and stumbling gait. CLINICAL FINDINGS: A splenic mass was identified on abdominal radiography and ultrasonography, and results of clinicopathologic findings indicated nonregenerative anemia, leukocytosis, and high serum C-reactive protein (CRP) concentration. To further investigate the cause of the dog's high serum CRP concentration, radiography and arthrocentesis were performed bilaterally on the carpal and stifle joints. On the basis of results, anemia of chronic disease associated with polyarthritis caused by the localized splenic mass was suspected. TREATMENT AND OUTCOME: After splenectomy, there were improvements in the dog's clinical signs, polyarthritis, nonregenerative anemia, and serum CRP concentration. The splenic mass was histologically diagnosed as a nonneoplastic splenic hyperplastic nodule with evidence of omental adhesion. CLINICAL RELEVANCE: Findings indicated that nonneoplastic splenic hyperplastic nodules could result in reactive polyarthritis, although such nodules have not to our knowledge been described previously as an underlying cause of polyarthritis. Therefore, veterinarians should investigate for nonneoplastic splenic hyperplastic nodules in addition to other typical underlying causes when treating dogs with polyarthritis.

Presumed reactive polyarthritis and granulomatous vasculitis in a Mississippi sandhill crane (Grus canadensis pulla).

A 1.5-year-old female Mississippi sandhill crane (Grus canadensis pulla) was presented and managed for a polyarthritis of the intertarsal and tarsophalangeal articulations. Results of aerobic bacterial cultures, Mycoplasma species culture, and polymerase chain reaction testing of articular fluid did not identify any causative organisms. Results of radiographs and cytologic examination of articular fluid were consistent with an inflammatory, nonerosive polyarthritis. The arthritis did not improve with systemic anti-inflammatory and antibiotic treatment and with joint lavage. A large necrotic granulomatous mass was detected on the right shoulder area from which Staphylococcus aureus and Enterococcus species were isolated as opportunistic pathogens. Two days after surgical resection of the mass, the distal polyarthritis resolved. Histopathologic examination of the mass was consistent with granulomatous vasculitis with abscess formation of unknown origin. In this crane, the unresponsiveness to standard therapy, the presence of an infected and inflammatory mass, and the resolution of the polyarthritis after the resection of the mass strongly supported a diagnosis of reactive immune-mediated nonerosive polyarthritis. Analysis of this case suggests that immune-mediated idiopathic arthritis should be a differential diagnosis of distal polyarthritis in cranes and that an inciting source remote from the joints should be investigated in case of lack of response to standard therapy.

Erosive polyarthritis associated with Mycoplasma gateae in a cat.

Erosive polyarthritis was diagnosed in an 11-month-old neutered male Egyptian Mau-cross cat with concurrent glucocorticoid-responsive dermatitis. Clinical signs, synovial fluid analysis, serological tests and radiographic appearance could not differentiate between immune-mediated and infective arthritis. Mycoplasma gateae was isolated by strictly anaerobic culture of the synovial fluid. Treatment with Enrofloxacin led to a rapid improvement of the cat's condition. Two months later the cat was euthanased because of severe glomerulonephritis and direct Coombs' test positive anaemia, possibly caused by mycoplasma infection. M gateae could not be isolated at post-mortem examination.

Etiology of reactive arthritis in Pan paniscus, P. troglodytes troglodytes, and P. troglodytes schweinfurthii.

The character of arthritis has not received the same attention in Pan paniscus as it has in P. troglodytes. Reactive arthritis (a form of spondyloarthropathy) in the latter has been considered to be either a sexually transmitted or an infectious-agent diarrhea-related disorder. The unique sexual promiscuity of P. paniscus enables us to distinguish between those hypotheses. The macerated skeletons of 139 adult P. paniscus, P. troglodytes troglodytes, and P. troglodytes schweinfurthii were macroscopically analyzed for osseous and articular pathologies. The sex of the animal was recorded at the time of acquisition. Twenty-one percent of the P. paniscus, 28% of the P. t. troglodytes, and 27% of the P. t. schweinfurthii specimens had peripheral and central joint erosive disease characteristic of spondyloarthropathy. Subchondral pauciarticular distribution and reactive new bone clearly distinguish this disease from rheumatoid arthritis, osteoarthritis, and direct bone/joint infection. The fact that P. paniscus and P. t. troglodytes were similar in terms of disease frequency makes the notion of sexual transmission unlikely. While the frequencies of spondyloarthropathy were indistinguishable among all species/subspecies studied, the patterns of joint involvement were disparate. The Pan paniscus and P. t. troglodytes home ranges are geographically separate. We assessed possible habitat factors (e.g., exposure to specific infectious agents of diarrhea) by comparing P. paniscus and P. t. troglodytes with P. t. schweinfurthii. The latter shared similar patterns and habitats (separated by the Congo River) with P. paniscus. The explanation offered for habitat-specific patterns is differential bacterial exposure-most likely Shigella or Yersinia in P. paniscus and P. t. schweinfurthii.

Management of reactive arthritis in a juvenile gorilla (Gorilla gorilla gorilla) with long-term sulfasalazine therapy.

A juvenile western lowland gorilla (Gorilla gorilla gorilla) experienced recurrent fever, lethargy, diarrhea, and/or arthritis starting at age 6 mo. During an episode at age 15 mo, Shigella sp. was isolated from diarrheic feces. At age 41 mo, reactive arthritis was diagnosed. In addition, the gorilla's growth was retarded. All arthritic attacks were managed symptomatically prior to age 4 yr, at which time a severe episode precipitated the implementation of therapy with sulfasalazine, an arthritis suppressive medication. Examination 27 mo later revealed cessation of progressive joint pathology although the animal exhibited decreased range of motion in most joints. The gorilla has been on sulfasalazine therapy for 4 yr without lameness. Growth has resumed, and there has been no radiographic evidence of progressive joint degeneration. Immunogenetic analysis of whole blood obtained at age 68 mo identified the gorilla major histocompatibility class I allele, Gogo-B*0101, which has limited nucleotide sequence similarity to HLA-B27, an allele associated with postinfection reactive arthritis in humans. Sulfasalazine therapy effectively managed reactive arthritis in this gorilla and should be considered for similarly frequently affected animals. Juvenile gorillas, in populations with a history of clinical shigellosis and/or postdiarrhea arthritis, may benefit from prophylactic sulfasalazine therapy after episodes of bacterial enterocolitis. Sulfasalazine therapy should be considered in all gorillas, juvenile and adult, experiencing confirmed Shigella sp.-associated enterocolitis.