Carpal hyperextension injury occurs when the ligaments in your pet's carpus tear. A dog's carpus can be equated with the human wrist and is located in the front leg. The backside of the carpus is supported by a network of dense ligamentous tissue called the "palmar carpal fibrocartilage," which prevents the joints from hyperextension. Most commonly, this injury occurs in mid-sized to large dogs after a fall or jumping from a height, but can be seen less frequently in cats and small breed dogs. In other cases, it is due to repeated, minor injury to the palmar fibrocartilage due to excessive weight or heavy activity. Hyperextension can also occur without trauma in pets with immune diseases of the joints. Small breed dogs are at greater risk of suffering this kind of collapse of their carpal joints. In these cases, the ligaments supporting the joints are destroyed by enzymes released by inflammatory cells.
Carpal hyperextension injury is most commonly seen as an acute injury. Warning signs of this condition include lameness in a front leg that worsens with exercise along with swelling and hyperextension of the carpus. When standing, a pet with carpal hyperextension injury will have their carpal joint collapsing towards the floor. Often, there is pain, swelling, and decreased range of motion associated with the carpal joint. This problem could happen bilaterally in the case of immune diseases.
Whenever your pet is showing signs of a health issue, your first step is to contact your primary care veterinarian. If it is thought your pet may suffer from carpal hyperextension injury or another serious condition, a veterinary specialist is available at an ExpertVet certified or affiliated hospital.