Carpal subluxation is a serious deformity of the forelegs, in which the pasterns, similar to a human's elbows, are weakened, sometimes to the point of laying flat against the ground when the dog walks. The condition can be genetic or due to physical trauma. There are a number of possible treatments for this condition, and it is important to consult your veterinarian as soon as possible.
What Causes Carpal Subluxation
Carpal subluxation involves a weakening and swelling of the tendons in the forelegs and either a gradual (in the case of genetic subluxation) or sudden (in the case of traumatic subluxation), dislocation of the bones between the dog's wrist and radius. Both forelegs are affected, although in the case of trauma, one may be more damaged than the other. Due to the nature of the trauma, either a fall or a jump from a high height, both forelegs will hit the ground at a similar force and be injured. If left untreated, the bones in the lower foreleg will become further separated over time, and the tendons may become hardened from the trauma of walking on the dislocated joints. The condition is most common in medium- to large-sized dogs and may be the result of a fall or high jump, degenerative genetic conditions, or immune-related diseases of the joint.
Nutritional Changes
Breeders and veterinarians have had some success with diet changes for dogs who appear to be genetically affected. Lowering the amount of protein, calcium, and phosphorous has been successful in some affected dogs, but the results are not yet conclusive. While a lower protein diet may not solve the problem, the German Shepherd Dog Club of America’s Internal Defects Committee suggests that a high protein diet may make the problem worse. Always talk to your veterinarian before starting a new nutritional regimen.
Splinting and Casts
Your veterinarian may suggest splinting or placing the forelegs in a cast to give the tendons and damaged tissues a chance to repair themselves. In the cast of immune-related joint disease, the vet will combine splinting and gentle exercise with an immunosuppressant. Unfortunately, splinting corrects the dislocation in less than 25 percent of cases. While the dislocated joints are relatively easy to reset in the correct positions, they also become dislocated again very easily. When splinting alone isn't enough, most veterinarians will recommend a surgical option.
Surgical Intervention
Surgical intervention is the most common and most frequently successful treatment of this condition. Most veterinarians recommend joint arthrodesis, a procedure that removes cartilage and encourages bone growth in the joint, stiffening the dislocated areas. While your dog may have a more limited range of motion after the procedure, the surgery has a high success rate. In some cases, your veterinarian may recommend stabilizing the joint using a T-plate fixation, a metal plate that runs along the carpal bones and stabilizes the region.
The Prognosis
Carpal subluxation is a serious condition, and if your dog is suffering from it, you should take him to a veterinarian immediately. Fortunately, with surgical intervention, most dogs will recover well. Although he will lose some range of motion, your dog may even be able to walk without a limp or noticeable fault in his gait.
References
- Grunfeld Shepherds: Carpal Subluxation and Weak Pasterns- Two Different Conditions?
- Vet Sports Medicine: Carpal and Tarsal Injuries
- The University of Sydney: Disorder - Carpal Subluxation
- Veterinary Specialty Center Tuscon: Surgery – Carpal Hyperextension Injury
- University of Pennsylvania: Fracture and Dislocation of the Carpus
- Veterinary Specialty Center: Antebrachial growth deformities: Closing Wedge Osteotomies And T-Plating Or Circular Fixator?