Immune-mediated polyarthritis (IMPA) is a condition where the immune system attacks joint tissues, causing painful inflammation in multiple joints simultaneously. It requires careful diagnosis and long-term management.
IMPA causes acute and significant pain — affected dogs experience joint swelling, heat, and pain on movement in multiple limbs simultaneously. Dogs with active polyarthritis are often severely lethargic, unwilling to bear weight, and distressed. Because the signs can mimic other conditions and joint taps are required for diagnosis, some dogs experience diagnostic delays during which pain is inadequately managed. Recurrent episodes cause cumulative joint damage and chronic discomfort. Long-term immunosuppression, while effective, requires monitoring for side effects including weight gain, increased infection risk, and muscle wasting. With appropriate management, most dogs achieve good quality of life — making early diagnosis and effective pain relief the most important welfare priorities.