Polyarthritis in Dogs

Polyarthritis is an inflammatory disease affecting the dog’s joints. It is similar to arthritis, but it affects more joints at the same time and is generally associated with autoimmune diseases. There are several types of polyarthritis in dogs, depending on the causes. Polyarthritis can be caused by infections or systemic disorders. Polyarthritis causes great pain in your dog, and therefore, it is important to monitor him and take him to the veterinarian for a checkup when you suspect joint problems.

Polyarthritis in Dogs

Polyarthritis in dogs is an inflammatory joint disease affecting more than 5 joints at the same time. It affects dogs regardless of sex, age or breed. Polyarthritis causes serious joint pain and interferes with normal movement. Polyarthritis destroys the cartilage lining of the joints.

Symptoms of Polyarthritis

These are the most common symptoms of polyarthritis in dogs:

  • Fever
  • Stiffness
  • Lameness in multiple limbs
  • Joint pain
  • Swollen joints
  • Reluctance to move

Sometimes polyarthritis can be difficult to diagnose, especially if there is no swelling in the joints.

Types of Polyarthritis

Depending on the cause, there are different types of polyarthritis affecting dogs. Polyarthritis can be caused by infections or autoimmune diseases. Immune-medicated polyarthritis can be erosive and non-erosive. The types of polyarthritis include the following:

  • Non-erosive polyarthritis—among the most common forms of polyarthritis in dogs. It is caused by antibodies that bind to foreign substances and invade the joints, causing inflammation. This type of polyarthritis is generally a secondary disease. It is most common in dogs with inflammatory bowel disease, mammary tumors or liver inflammation or in dogs undergoing specific treatments (phenobarbital, pen­i­cillin and trimethoprin-sulfa). Generally, once the primary condition is treated, polyarthritis resolves as well.
  • Immune-mediated polyarthritis—a very common form of polyarthritis. Autoimmune diseases, such as lupus, cause the immune system cells to attack the dog’s own cells. Antibodies can destroy or inhibit the normal function of joint cells, causing polyarthritis. Autoimmune diseases also attack the nerves and organs (kidneys, skin, eyes, etc.). The treatment consists of immunosuppressive medication.
  • Rheumatoid arthritis—can affect multiple joints. This type is most common in middle-aged or senior toy dogs. Rheumatoid arthritis erodes the cartilage and the treatment is based on immunosuppressive medication. Treatment only controls the disease; it does not cure it.
  • Septic polyarthritis—due to infectious organisms. This form of polyarthritis is not very common in dogs and can be managed through treatment if diagnosed in due time.
  • Idiopathic polyarthritis—a form of polyarthritis with unidentified causes. It is diagnosed by excluding all possible causes. Idiopathic polyarthritis is more common in sporting and large breeds. The treatment of choice is based on prednisone. Some dogs might require lifelong medication.

Some breeds are more prone to specific immune-mediated polyarthritis. In shar-peis, for instance, polyarthritis manifests through swelling of the carpal joints. This condition cannot be treated. Breed-specific polyarthritis has been also reported in Akita Inus, Bernese mountain dogs, beagles, boxers, German short-haired pointers and Weim­a­ran­ers. Some breeds respond well to immunosuppressive medication, while in others, the disease is more difficult to manage.