Canine immune‐mediated polyarthritis: A review of 84 cases in the UK between 2011 and 2021

Abstract

BackgroundImmune‐mediated polyarthritis (IMPA) is a well‐recognised disease in dogs, but studies evaluating the response rates, relapse rates and long‐term outcomes are scarce.ObjectivesTo provide an updated description of the signalment, clinical signs, clinicopathological findings, distribution between subgroups, rates of response and relapse and long‐term outcome of 84 dogs diagnosed with IMPA at a single referral hospital.MethodsDogs diagnosed with IMPA between January 2011 and December 2021 were identified. Dogs with neutrophilic inflammation in ≥2 joints were included. Cases with <1 month of follow‐up, or those missing pertinent data, were excluded.ResultsA total of 84 cases were included. An initial response was achieved in 77/84 (92%) cases. Of the cases that initially responded, 37/77 (48%) suffered at least one relapse and 18/77 (23%) suffered multiple relapses. Indefinite treatment was recommended in 17/84 (20%) cases. Of the 70 dogs for which at least 12 months of follow‐up data were available, 12/70 (17%) were euthanised due to IMPA or for unknown reasons.ConclusionIMPA carries a fair prognosis, but relapses occur in many cases and euthanasia due to relapsing or refractory disease is not uncommon.