Immune-Mediated Polyarthritis (IMPA) in Dogs
Immune-Mediated Polyarthritis (IMPA) is a medium-severity autoimmune condition that can affect dogs of all ages and breeds. IMPA is a non-erosive inflammatory joint disease caused by immune complex deposition in synovial membranes. Dogs present with multiple swollen, painful joints and systemic illness. It is usually idiopathic but can be secondary to infection or neoplasia. It is documented across 5 breeds, though prevalence and severity can differ significantly between them. It typically becomes apparent at 2-6 years. Early signs to watch for include shifting lameness, multiple swollen painful joints, fever, and lethargy. When treatment is required, costs are estimated at £500-£2,000/year depending on severity, location, and the specific intervention needed. This page covers symptoms, treatment options, and preventive steps — along with breed-specific information where available.
Signs & Symptoms
The following symptoms are commonly associated with Immune-Mediated Polyarthritis (IMPA) in dogs. If your dog displays several of these signs, consult your vet promptly — early diagnosis typically leads to better outcomes.
- Shifting lameness
- Multiple swollen painful joints
- Fever
- Lethargy
- Lymphadenopathy
- Joint stiffness
Treatment Overview
Immunosuppressive prednisolone is highly effective for idiopathic type I IMPA. Secondary forms require treatment of the underlying cause. Long-term tapering doses prevent relapse.
Typical onset: 2-6 years
Prevention & Screening
While not all cases of Immune-Mediated Polyarthritis (IMPA) can be prevented, the following steps reduce risk or enable earlier intervention:
- No proven prevention
- Treat infectious diseases promptly to prevent immune-complex deposition
Estimated Treatment Cost
Treatment for Immune-Mediated Polyarthritis (IMPA) is estimated at £500-£2,000/year, depending on severity, the specific intervention required, and your location. Costs may be higher for surgical procedures or ongoing management. Comprehensive pet insurance covering this condition is strongly recommended.
Breeds Affected by Immune-Mediated Polyarthritis (IMPA)
The following 4 breeds are documented as being susceptible to Immune-Mediated Polyarthritis (IMPA). Click any breed to view breed-specific information about this condition, including prevalence and recommended screening.
Looking for more information? Browse all dog health conditions or explore the health guides for in-depth breed care advice.