CAUSES OF CLUB FOOT
Most cases of club foot develop in foals. Although the specific causes are not fully understood, several factors, alone or in combination, may be involved. Club foot often accompanies congenital limb deformities, which develop within the mare’s uterus and are present at a foal’s birth. Acquired limb deformities develop later, if a foal’s bones and tendons grow at different rates. “Often there is a nutritional component,” says Travis Burns, CJF, lecturer and chief of farrier services at the Virginia–Maryland College of Veterinary Medicine. “Foals need a wellrounded, balanced diet that does not go beyond the nutritional requirements.”
A diet overly rich in calories and nutrients puts young horses at risk for developmental orthopedic disorders (DOD), a collection of bone and joint abnormalities including osteochondritis dessicans (OCD), subchondral bone cysts, physitis and other serious problems.
The pain from any of these conditions can cause a young horse to load the feet in an abnormal way that enables a club foot to develop. “Often the club foot or feet are secondary to OCD lesions in the shoulder, for instance,” says Burns. If it’s painful for the horse to put weight on that limb, the flexor muscles eventually contract and pull the heel up, and the horse puts more load on the toe. With less wear on the heels, they grow longer and create the upright foot.
Genetics, too, may play a role---club foot seems to develop more often in certain families of horses. “There probably is a genetic component but I also wonder if it’s partly management,” says Mike Pownall, DVM, a veterinarian/
farrier with McKee-Pownall Equine Services in Campbellville, Ontario. “If the mares are all foaling at the same farm and getting the same feed, there may be some environmental causes such as nutrition.”
In fact, all of these factors may work together: A horse genetically programmed for fast growth, who also gets excess nutrients, may experience developmental problems that lead to discomfort or pain, all of which creates a club foot.
“Some years back I had the opportunity to work on a number of horses that were sired by a very popular local Thoroughbred stallion during the 1980s and early ’90s,” says Tia Nelson, DVM, a veterinarian/farrier from Valley Veterinary Hospital in Helena, Montana. “About 75 percent of his offspring ended up with a club foot on the right front. These were colts and fillies that I’d seen from the time they were born. With all of them, the club foot appeared quickly, between one trimming and the next, when they were about a year and a half of age. I know there was a genetic component because that particular stallion produced a lot of foals that ended up this way.”
Nevertheless, Nelson adds that multiple factors may have been involved in these horses’ problems: “I think it was a pain response. I think what happened is that they had OCD in their elbow or shoulder, and because of the pain from those bony lesions they avoided putting full weight on that limb.”
Club foot can develop in mature horses, too, for similar reasons---any injury or chronic pain that causes a horse to consistently favor one foot can lead to contracting and shortening of the muscles and tendons (specifically the deep digital flexor tendon and muscle apparatus) in that leg, eventually pulling the foot into a more upright position.
“I watched one young Paint horse become club-footed through the course of a summer,” says Nelson. “He also started bucking. I finally looked at his saddle and saw that it was very badly twisted. When this horse was ridden with a different saddle, he didn’t resist and he didn’t buck. When his owner got rid of the saddle with the twist, this horse went back to normal in his attitude, and his normal hoof growth resumed.”
Infrequent or improper trimming may also lead to, or worsen, a club foot in horses of any age. Trims that leave a horse’s feet mismatched or unbalanced may leave him with an uneven stride and/or a rough gait that causes him to consistently lift his heels and place weight on his toes in a way that, over time, forces the hoof horn to grow faster at the heel than at the toe.
DISTORTED: Severe cases of club foot can cause serious deformations in the hoof, including a deeply dished hoof wall, a very high heel and widely divergent growth rings.
OPTIONS: No one treatment is “best” for a club foot, but most cases can be improved with skilled care. Many horses with a mild club foot have productive careers.