Canine polyarthritis is an inflammatory disease which impacts multiple joints. Polyarthritis can be infectious or non-infectious, and the non-infectious cases are further broken down into four types. Type IV immune-mediated polyarthritis is caused by an adverse vaccine reaction. Most cases of canine polyarthritis are immune-mediated polyarthritis. Some breeds may be predisposed to an adverse reaction following vaccination because they possess immunodeficiencies (failing immune system). Weimaraners and Akita Inu are two such breeds.
Immune-mediated polyarthritis can occur following the first vaccine injection or after booster vaccinations. Inflammation of the joint lining causes and increase in white blood cells within the joint fluid. This causes joint swelling and pain. The arthritis is normally self-limiting (does not progress) and can automatically resolve within a week. More severe symptoms may be associated with this disease. Keep accurate vaccination records on dogs displaying symptoms of polyarthritis.
Dogs experiencing immune-mediated polyarthritis will suffer from varying degrees of lameness. They may display a stiff gait, shifting leg lameness, reluctance to rise or are generally lethargic. Fever may accompany this disease as well as bilaterally symmetrical swollen painful joints.
Have a veterinarian perform a complete physical and orthopaedic exam. Complete a CBC (blood test), urine analyses and biochemical profile. Take radiographs of the affected joint or joints. Arthrocentesis (joint aspiration) will reduce pain and swelling by removing excess fluid from the joint. Synovial fluid analysis of several joints and diagnostic imaging of the thorax and abdomen will help exclude or identify any underlying diseases.
Initial treatment involves pain relieving analgesics and the broad spectrum antibiotic doxycycline. Immunosuppressive therapy is implemented with prednisolone or other corticosteroid. High prednisolone doses are given for two weeks. Reduce the dose gradually over the next few months based on veterinarian recommendation. Dogs may show improvement within days but maintenance therapy is critical to prevent relapses. Continual low doses of prednisolone may be needed to keep the dog in remission. Intravenous fluids may be required for debilitated animals. Initially, strict rest is recommended. Normal activity can resume upon improvement.
Monitor the dog's condition for improvement, deterioration or relapse. Relapse may occur when the therapy drugs are decreased. A slow and lengthy decrease in dosage is crucial for preventing a relapse. Dogs on immunosuppressive therapy are more susceptible to infection. Watch for changes in behaviour, appetite or general condition. Certain immunosuppressive drugs require periodic blood tests. Future vaccination should be used with caution or eliminated.