Arthritis in Dogs

Cartilage acts like a cushion between the bones in a joint, letting them glide past each other without pain. Arthritis develops when that cartilage becomes damaged and the joint grows inflamed and painful as a result. There are over 100 recognized forms of arthritis in humans; in dogs, the most common by far is osteoarthritis, also known as degenerative joint disease. Less commonly, dogs can also develop rheumatoid arthritis or septic arthritis, caused by a joint infection.

Arthritis tends to affect middle-aged and older dogs most, though younger dogs aren't immune to it. Because the condition often develops gradually alongside normal aging, it's easy to write off early signs like a slight loss of playfulness as just "getting older," when your dog may actually be in significant pain.

• Osteoarthritis

  Osteoarthritis is the most common form, largely caused by everyday wear and tear on the joint, though it can also follow an injury. It begins with cartilage damage, which, left unaddressed, eventually leads to the bones themselves wearing against each other. What starts as mild discomfort during activity can progress into constant pain, even at rest. Osteoarthritis most often affects weight-bearing joints but can involve joints of any size, and unlike rheumatoid arthritis, it's primarily a condition of older dogs. There's no cure, but its progression can be slowed and managed. Physiotherapy that strengthens the surrounding muscles and joints can help, as can pain medication, and for some dogs, weight loss meaningfully reduces the load on affected joints.

• Rheumatoid arthritis

  Rheumatoid arthritis happens when the immune system mistakenly attacks the body's own tissue, not just in the joint, but more broadly throughout the body. This leads to damage in the joint lining and cartilage, and eventually erosion of the bones that meet at the joint. Corticosteroids are among the medications used to manage this condition.

• Genetics

  Larger breeds such as Labradors, Retrievers, German Shepherds, and Alaskan Malamutes carry a higher risk of hip dysplasia than smaller breeds.

• Injury or Trauma

  Fractures, dislocations, and other joint injuries can alter joint development and function, often leading to secondary osteoarthritis.

• Obesity

  No evidence it directly causes arthritis, but it can significantly worsen an existing case.

Arthritis affects roughly one in five adult dogs in the U.S., making it one of the most common sources of chronic pain veterinarians treat. The joints most often affected are the hips, elbows, shoulders, knees (stifles), wrists (carpi), ankles (hocks), and spine.

A veterinarian can diagnose arthritis through a physical exam, often supported by X-rays. In some cases, blood work or a sample of joint fluid may be needed to rule out infection as a cause.