Ankylosis in Horses

 

Ankylosis is the term for when a damaged joint has become fused, usually as a result of chronic or severe joint disease. When a joint ankyloses, it is unable to flex or extend, and it doesn’t matter how old the horse is. This is most often the result of a bacterial infection within the joint (called a septic joint, or septic arthritis). This infection degrades the cartilage between the two bones, causing the bones to fuse together. Other times, ankylosis is a surgical procedure, called arthrodesis, that is sometimes performed for joints that don’t have large ranges of motion. This procedure is performed to allow for stability in a joint that has been destroyed by severe osteoarthritis.

 

Symptoms and Types

 

• Stiffness in muscles and joints
• Inability to move joints
• Lameness

 

Causes

 

• Septic arthritis
• Elective surgery
• Trauma to the joint

 

Diagnosis

 

A veterinarian can diagnose ankylosis upon inspection of the affected area and radiographs (x-rays). There is no treatment for ankylosis. Unfortunately, it is an irreversible condition resulting in permanent lameness. In cases where it is purposely done surgically, the horse is usually not lame, but may walk with a stiff gait due to the inability to properly bend that particular joint. Surgical arthrodesis is only performed in low-motion joints, such as those below the fetlock.

 

Living and Management

 

Because horses with ankylosis become lame, special accommodations must be made for the horse, including a comfortable living space and easy access to food and water.

 

Prevention

 

Prevention is difficult for ankylosis. It can affect a horse of any age and may even be the result of a deformity from birth (congenital).