Health Watch: Foot and Limb Deformities

Compiled by staff

Foot and Limb Deformities in Foals, AAEP 2008
In a presentation to the American Association of Equine Practitioners on hoof deformities in foals and recommendations for correcting or managing them, Dr. Bob Hunt of Hagyard Equine Medical Institute in Lexington called for caution, especially in trying to use hoof trimming/extensions to correct a limb deformity.
“Don’t let the foot become a victim of the disease; don’t fix the leg with the foot,” he advised. “A lot of time you’re already behind the eight ball and the foot is already a casualty. Everything in life should be done in moderation, especially what we do with juvenile horses; very commonly our aggressive measures are to the detriment of the animal.”
When multiple deformities are present, he advised treating the lower ones first: “You’ve got more time to work with knees (before the growth plates close, at which point bone growth can no longer be altered), so fix fetlocks first.
“The number one thing to keep in mind with all problems is to keep the foot balanced, tracking right (foot flight is straight), and breaking over the center,” he said. “If the foal is crooked, but tracks properly, I’m not messing with him because if I change him, he’ll track badly.”

Summer is Prime Time for Potomac Horse Fever
With summer just around the corner, now is the time to protect horses against Potomac horse fever via vaccination and management measures.
“Horse owners need to be aware of the disease and its seasonality,” said Dr. Julia Wilson of the University of Minnesota.
Potomac horse fever is a potentially deadly disease that can cause mild depression, anorexia, diarrhea, and abortion. Some horses develop severe toxemia, and up to 40% of horses with PHF develop laminitis.
Horses contract PHF by ingesting aquatic insects, such as caddis flies and mayflies, that are infected with the causative agent Neorickettsia risticii. Traditionally, veterinarians see PHF cases in the summer and early fall, during the insects’ peak hatching times. Horses consume these infected aquatic insects while grazing near waterways.
Caddis flies, mayflies, and other carriers also swarm around barn lights, which means stabled horses can be exposed.
“Insects like to swarm around lights,” explained Dr. Frank Hurtig, director of Veterinary Services for Merial. “That’s why it’s so important to keep hay and water away from lights that stay on all night. Once those infected insects die, they may fall directly into the horse’s food and water source.”

Researcher Said Swine Flu in Horses ‘Unlikely’
Can horses get swine flu? Probably not, said Dr. Tom Chambers, head of the World Organization for Animal Health’s Equine Influenza Reference Laboratory at the University of Kentucky’s Gluck Equine Research Center in Lexington.
Influenza viruses have an amazing ability to mutate and change their characteristics, so scientists who study them never say “never.” But, while it’s not impossible for a horse to get swine influenza, Chambers said it’s unlikely.
“Swine flu in humans is not novel,” Chambers said. “Swine flu in horses would definitely be novel.”
Horses can and do get equine influenza, which is one of the most common causes of equine upper respiratory disease. It is highly contagious, and horses can spread flu virus through direct contact or coughing. To learn more, watch the Webinar “Understanding Equine Influenza” at

965 U.S. Horses Exposed to CEM
The ongoing investigation into contagious equine metritis now includes more than 965 exposed or positive horses, according to the USDA. The investigation began in mid-December 2008, when a Quarter Horse stallion on a Kentucky farm tested positive during routine screening for international semen shipment. At least one Thoroughbred stallion has been identified as positive by the World Organization for Animal Health, but that stallion has had very limited use as a breeding stallion and all through semen collection and artificial insemination, with no live-cover breeding reported.

Excerpted from The Horse: Your Guide to Equine Health Care. Free weekly newsletters at