Idiopathic localized eosinophilic synovitis in a cat.
A 4-year-old male castrated Seal Point Himalayan cat was presented for evaluation of right thoracic limb lameness of 6 weeks duration. Synovial fluid analysis of the swollen right carpal joint revealed a mixed cell synovitis, with a total nucleated cell count of 13,200/microliter and 34% eosinophils. A diagnosis of idiopathic localized eosinophilic arthritis was made. Additional clinical and diagnostic findings included mild lymphadenopathy with lymphoid hyperplasia and an antinuclear antibody titer of 1:320. Lack of multisystem involvement made systemic lupus erythematosis unlikely. Immunosuppressive therapy with oral prednisone alleviated the lameness. Eosinophilic synovitis has not previously been reported in cats. An immune-mediated mechanism was likely in this case; however, the exact etiology remains unknown.
Silverstein
Deborah C.
DC
Veterinary Medical Teaching Hospital, University of California, Davis, CA 95616, USA. dcsilverstein@ucdavis.edu
Almy
Frederick S.
FS
Zinkl
Joseph G.
JG
Christopher
Mary M.
MM