C-reactive protein concentration in canine idiopathic polyarthritis.

To investigate the clinical utility of C-reactive protein (CRP) in idiopathic polyarthritis (IPA), its concentration was measured in dogs with IPA. The CRP concentration was markedly increased in all the IPA dogs at the time of diagnosis and decreased significantly in response to the initial corticosteroid treatment; this indicated that CRP can be used as an index for therapeutic response in IPA cases. Furthermore, at 6 months after the diagnosis, a significant association was observed between the CRP concentration at follow-up (6-13 days after the treatment was started) and the frequency of medication ("no or seldom-medicated (NSM)" groups or "continuing medication (CM)" groups). These results suggest that the initial response of CRP to corticosteroid treatment may be a prognostic factor of canine IPA.