Pinpointing the causes of laminitis.

"As a veterinary specialist at a referral hospital, Dr. John Peroni must often treats horses with severe laminitis, a painful and debilitating hoof condition. By the time he sees these animals, it often is too late to save them. Those horses who do survive often suffer permanent lameness.

"The majority of these horses are difficult to treat successfully," says Dr. Peroni. says. "That fires me up to get this disease under control."

Laminitis is an inflammation of the horse's laminae, connective tissues located between the hoof and underlying bone. When the area becomes inflamed, the swelling causes this delicate junction to break down. The hoof's weight-bearing abilities are lost, and the horse develops lameness.

"Laminitis is very painful," Dr. Peroni says. "Horses are lost either because of unrelenting pain or the underlying disease that led to laminitis."

With Foundation funding, Dr. Peroni and his colleagues at The University of Georgia are making strides toward understanding laminitis. They recently made a major breakthrough in identifying the circulation process inside the horse's hoof, an important step toward developing effective treatments for this common problem. Treating laminitis is particularly problematic because it usually occurs when the horse is already ill. Any disease that causes inflammation, such as colic or colitis, can lead to laminitis. So the veterinarian must treat the primary condition, as well as the laminitis.

The horse's foot is extremely difficult to study. Because the laminae are located between the bone and the hoof, they are nearly impossible to access. The blood vessels of the hoof are tiny, just a bit wider than the diameter of a human hair. In this study, Dr. Peroni was able to isolate the blood vessels and study them for the first time. Under normal conditions, blood flows evenly into the foot through the arteries and out through the veins. However, Dr. Peroni learned that with laminitis, the veins are constricted, so less blood can leave the foot. This causes the tiny capillaries between the arteries and veins to leak. Although further studies are needed to confirm the results, this study indicates that veno-constriction in the laminae is responsible for laminitis.

"Now if we can develop specific vein dilators, it would be a significant treatment breakthrough," Dr. Peroni says. His next goal is to discover what causes the veins to constrict and then determine a medication that could counteract that process. The results could get horses with laminitis back on their feet in no time.