05/26/2026
Arthritis Awareness Month: Osteoarthritis aka "arthritis"
When most people hear the word 'arthritis', they're thinking of osteoarthritis-- with good reason! Osteoarthritis (OA) is by far the most common type of arthritis in dogs & cats! It's MUCH more common than septic arthritis or immune-mediated polyarthritis (IMPA) which were discussed earlier.
Can you believe it? 😳 More than 90% of dogs older than 5 years have osteoarthritic (OA). Even young dogs don't go unscathed: 20% of dogs under 1 year of age have arthritis. OA is more difficult to diagnose in our felines, but more than 90% of cats older than 12 years old live with osteoarthritis.
Osteoarthritis refers to age or trauma-related injury and degeneration of the joint cartilage, which sparks arthritis aka inflammation of the joints (heat, swelling, pain, and excess production of joint fluid). With time, OA often causes the body to put down excess bone that grows in and around the joint, known as osteophytes. Horse people affectionately call these osteophytes "joint mice", for reasons many people never fully understand.
*** The xray on the left shows marked hip arthritis: Look how large and blunted the femoral heads are, and the triangular "joint mice" just above them. The xray on the right shows a pair of normal hips for comparison.
OA can be caused by numerous underlying issues:
- Wear and tear on the joints from heavy exercise or obesity
- Imperfect joint development such as hip dysplasia or elbow dysplasia
- Limb deformities such as bowing of the forelegs, carpal valgus, or post-legged hind end conformation
- Old leg fractures that healed incorrectly or poorly
- Cartilage defects such as osteochondrosis dissecans (OCD)
- Unstable knees, spinal instability, or hypermobile kneecaps (known as luxating patellas)
