Immune-Mediated Polyarthritis, IMPA (Inflammatory Condition of Multiple Joints) in Dogs

  • Occurrence: very rare
  • Location of illness: General/Whole body, Legs
Content
Download/Print

Immune-mediated polyarthritis (IMPA) in dogs is an inflammatory condition in which the animal’s immune system attacks multiple joints, leading to Pain, Swelling, and limited mobility.

The most important facts at a glance

Immune-mediated polyarthritis (IMPA) is an autoimmune disease in dogs in which the immune system mistakenly attacks and inflames the joints. The exact cause is unclear, but genetic factors and certain dog breeds appear to be predisposed. IMPA can occur primarily without other underlying conditions or secondarily due to infections, medications, or vaccination reactions. Hormonal and environmental influences such as stress can also influence the disease.

Symptoms of IMPA include Fever, joint Swelling, Pain, stiff gait, and Lameness. Diagnosis is made through clinical examinations, blood tests, X-rays, and joint fluid analysis. These tests help to rule out other causes and identify the inflammation. Treatment aims to reduce inflammation and relieve Pain. Non-steroidal anti-inflammatory drugs (NSAIDs) and immunosuppressants such as prednisone or azathioprine are commonly used. Complementary therapies such as physiotherapy and dietary supplements can support recovery.

The prognosis depends on the severity of the disease and the response to treatment. Many dogs achieve a good quality of life, especially with early diagnosis. However, chronic problems and permanent joint damage are possible. Regular veterinary follow-up is crucial to monitor the course of the disease and adjust therapy. Since the cause of IMPA is not fully understood, there are no specific prevention measures. However, a balanced diet, regular examinations, and careful monitoring after vaccinations or medication administration can be helpful.

Causes

IMPA belongs to a group of autoimmune diseases in which the body’s immune system attacks its own cells or tissues. In IMPA, the joints are affected, leading to inflammation. The exact mechanism as to why the immune system considers the joints foreign and attacks them is not yet fully understood. Scientists suspect that genetic predispositions play a role, as certain dog breeds are more frequently affected.

The disease can occur primarily without other underlying conditions, or secondarily in connection with other systemic diseases, infections, or as a reaction to medications. Secondary forms of IMPA can be triggered by infections such as Lyme disease, or even by vaccination reactions.

Hormonal and environmental influences can also play a role. For example, hormonal changes in non-neutered female dogs can cause an exacerbation of symptoms. Environmental factors such as stress or other diseases can increase the risk of developing IMPA.

Symptoms

The symptoms of IMPA can vary from dog to dog, but typically include Lameness and Pain in multiple joints. This Lameness can migrate, meaning it can switch between different legs.

Affected dogs often show an aversion to exercise, are lethargic, and may show signs of Fever. The joints may be swollen and warm to the touch. In some cases, there may be general malaise and loss of appetite, indicating the systemic nature of the disease.

Additionally, joint noises or creaking may occur during movements, and in advanced cases, there may be a significant restriction of joint mobility, which greatly affects the dog’s everyday life.

Diagnosis

The diagnosis of IMPA requires a comprehensive clinical examination and consideration of the dog’s medical history. A veterinarian will often perform a combination of blood tests, X-rays of the affected joints, and, if necessary, a joint fluid analysis.

Analysis of the joint fluid can reveal elevated white blood cells and signs of inflammation, suggesting an immune-mediated cause. Blood tests can help rule out other causes and assess the animal’s general health.

In some cases, further tests such as ultrasound or computed tomography (CT) may be necessary to rule out other conditions that could cause similar symptoms. An accurate diagnosis is crucial to initiate appropriate therapy.

Therapy

The treatment of IMPA aims to reduce inflammation and relieve Pain in order to improve the dog’s quality of life. Non-steroidal anti-inflammatory drugs (NSAIDs) are often used to control inflammation and Pain.

In many cases, however, immunomodulators or immunosuppressants are needed to dampen the overactive immune response. Medications such as prednisone or azathioprine may be prescribed to suppress the immune system and control the inflammatory response.

Complementary therapies such as physiotherapy, acupuncture, or the use of dietary supplements such as omega-3 fatty acids can also be helpful in supporting joint health and further alleviating symptoms.

Prognosis and follow-up care

The prognosis for dogs with IMPA varies depending on the severity of the disease, the response to treatment, and the presence of concomitant diseases. Many dogs respond well to treatment and can achieve a good quality of life, especially if the disease is diagnosed and treated early.

However, some dogs may develop chronic problems that require long-term treatment. In rare cases, IMPA can lead to permanent joint damage that impairs the dog’s mobility.

Regular follow-up by the veterinarian is crucial to monitor the course of the disease and adjust therapy if necessary. Owners should be prepared that treatment may be required for life to prevent relapses.

Prevention

Since the exact cause of IMPA is not fully understood, there are no specific measures to prevent the disease. Nevertheless, some general measures can help to reduce the risk.

A balanced diet and a healthy lifestyle can support the dog’s general health and strengthen the immune system. Regular veterinary examinations can help to detect early signs of the disease and treat it in time.

Since some medications or vaccinations are considered triggers for secondary forms of IMPA, these should only be administered after consultation with a veterinarian and when medically necessary. Careful monitoring after vaccinations or medication administration can help detect early signs of a reaction.

Content
Download/Print