Prospective randomized trial comparing relapse rates in dogs with steroid-responsive meningitis-arteritis treated with a 6-week or 6-month prednisolone protocol

Abstract

Background: Traditionally, 6-month courses of prednisolone are used to treat steroid-responsive meningitis-arteritis (SRMA), but this medication is associated with adverse effects that can lead to poor quality of life. Hypothesis/Objectives: Resolution of clinical signs and rate of relapse of SRMA would not be significantly different between a 6-month prednisolone protocol and a 6-week protocol. Animals: Forty-four hospital cases from multiple referral centers in the United Kingdom (2015-2019). Twenty of 44 were treated with the 6-month protocol and 24/44 with the 6-week protocol. Methods: Prospective, randomized trial with 12-month follow-up. The same prednisolone protocol reinitiated in the event of relapse. Analysis of relapses with binary logistic and Poisson regression modeling. Results: All cases responded to their treatment protocol. Relapses occurred in 6/20 (30%) of the 6-month protocol and 9/24 (38%) of the 6-week protocol. There was no statistical difference in the incidence risk of at least 1 relapse between the 2 groups (odds ratio = 1.40; 95% confidence interval [CI], 0.40-4.96, P = 0.60). Among the 15 dogs that relapsed, 10/15 (67%) relapsed once, 3/15 (20%) relapsed twice, and 2/15 (13%) relapsed 3 times. No statistical difference was detected in the incidence rate ratio (IRR) of total relapse events between the 2 groups (IRR = 1.46; 95% CI, 0.61-3.48; P = 0.40). Conclusions and Clinical Importance: “Short” 6-week prednisolone protocols could be used to treat SRMA, thereby presumably reducing the duration and severity of prednisolone's adverse effects.