Description and outcome of dogs with primary immune‐mediated polyarthritis: 73 cases (2012‐2017)

Abstract

Objectives: To provide a description of primary idiopathic immune-mediated polyarthritis, including longterm outcome and relapse rates, for dogs starting treatment with corticosteroids alone or corticosteroids with a second immunosuppressant.Materials and MethOds: Medical records were reviewed between January 2012 and December 2017 to identify dogs diagnosed with primary immune-mediated polyarthritis. Data including signalment, clinicopathological findings, type and duration of treatment, relapse and outcome were recorded.results: Seventy-three dogs were included. Fifty-four dogs were started on corticosteroid monotherapy (an additional immunosuppressant was introduced later in 27/54 dogs) and 19 dogs were treated with multi-modal immunosuppression from the outset. Ninety-five percent (69/73) of dogs responded favourably to therapy although death was attributed to immune-mediated polyarthritis in 19% (14/73) of dogs. Relapse of clinical signs was reported in 53% (39/73) dogs (31/39 while on treatment), with multiple relapses observed in 17 dogs. Complete cure (permanent withdrawal of immunosuppressive medication) was achieved in 46 dogs (63%). Overall, 81% of dogs had a well-managed disease for an extended timeframe (≥1131 days). Fourteen of 19 (74%) dogs that started treatment with multi-modal immunosuppression and 32 of 54 (59%) started on corticosteroids alone achieved a complete cure.clinical significance: This study provides extended follow-up information for a large cohort of dogs with primary immune-mediated polyarthritis. Immunosuppressive therapy was discontinued in the majority of dogs but disease-associated mortality remains high.

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

“…Rates of response to treatment were high, as previously reported (Stone, 2017a;Ravicini et al, 2022;Johnson & Mackin, 2012b). The number of dogs with long-lasting remission, representing 62% of dogs in the present study, differed from 0% to 63% in previous publications (Bennett, 1987;Clements et al, 2004;Ravicini et al, 2022).…”

“…This could suggest that the use of a secondary immunosuppressive drug may not achieve higher long‐term remission rates. Furthermore, in the most recent study on primary IMPA (Ravicini et al., 2022 ) dogs treated with prednisolone and a second immunosuppressive drug did not necessarily achieve better outcomes than those treated with prednisolone alone.…”

“…It could be speculated that this discrepancy results from disparities in treatment used between studies, (Stone, 2017a ; Bennett, 1987 ; Clements et al., 2004 ; Shaughnessy et al., 2016 ; Johnson & Mackin, 2012b ; Colopy et al., 2010 ; Sato et al., 2017 ; Tamura et al., 2020 ; Whitworth et al., 2019 ; Bergh et al., 2021 ) particularly as some of the therapies used have fallen into disuse due to their adverse effects (Wallisch & Trepanier, 2015 ; Matsuyama et al., 2017 ) or lack of evidence of effectiveness (Bergh et al., 2021 ). However, prednisolone was administered in both the study with zero long‐lasting remissions and a more recent study with a 63% rate of ‘complete cure’ (Bennett, 1987 ; Ravicini et al., 2022 ). Therefore, the different outcomes obtained seemed unrelated to the choice of drugs, or at least to the use of prednisolone.…”

“…Previous studies have described IMPA in dogs, since first diagnosed in the 1970s (Stone, 2017a ; Johnson & Mackin, 2012a ; Bennett, 1987 ; Rondeau et al., 2005 ; Clements et al., 2004 ; Stull et al., 2008 ; Shaughnessy et al., 2016 ; McKenna, 2020 ; Jacques et al., 2002 ; Pederson et al., 1976 ). The clinical course of canine cases in the United Kingdom has not been re‐evaluated since the 1980s (Bennett, 1987 ), although a recent UK‐based study described the response and relapse rates to current therapies (Ravicini et al., 2022 ).…”

Comparison of timing of relapse in dogs with nonassociative immune‐mediated hemolytic anemia, thrombocytopenia, or polyarthritis

“…[5][6][7] Relapse of clinical disease is a possible feature of all immunemediated conditions and is a concern for both clinicians and owners because relapses may be associated with increased morbidity or mortality. Reported prevalence of relapse ranges between 11% and 24% 5,[8][9][10][11] for IMHA, 9% and 39% 6,[12][13][14] for ITP, and 20% and 48% 3,15,16 for IMPA. However, it remains unclear whether or not the likelihood of relapse decreases with time after diagnosis, and whether or not the timing of relapse after diagnosis is similar among all 3 diseases.…”