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Is Cold Weather Hoof Pain Laminitis? Not Necessarily

Though cooler weather energizes most horses, dropping temperatures can be a pain—literally—for horses that develop hoof pain as temperatures drop. Though what is considered “too cold” can vary by horse, some horses become painful in temperatures just above freezing: 40 degrees F. Pain generally disappears as soon as the temperature rises above this threshold.

Though it's sometimes called “winter laminitis,” there's no evidence of inflammation and often no changes that can be discerned on an X-ray. The cause is a failure of the hoof to effectively respond to changes in circulation caused by the cold. This cold-induced pain is temporary, but can be significant.

In a healthy horse, cold temperatures will cause the blood flow to limbs and hooves to be reduced. Cold temperatures cause the arteriovenous shunts in the hooves to open and divert blood back to the horse's core to preserve body heat. This mechanism will also periodically close the shunts and send blood to the tissues so that oxygen and nutrient levels don't get too low.

This system doesn't work in horses that have cold-induced hoof pain; the tissues don't receive shunts open, but don't occasionally send adequate blood flow to the hooves.

Horses with cold-induced hoof pain can be assisted by blanketing them to help conserve body heat. Wrapping their legs can also help; lined shipping boots work well as they cover the heels and coronary band, preventing rain and snow from getting into the boots. Adding Jiaogulan, a Chinese herb, to an affected horse's diet may also help. Jiaogulan stimulates the production of nitric acid, which is turned into a potent vasodilator in the body.

Though painful, cold-weather hoof pain is temporary and can be managed to keep a horse more comfortable.

Strangulating Lipoma: Surgery The Only Option

Strangulating lipomas are a common cause of colic in horses older than 10. These fatty tumors take years to develop; they eventually wrap around the small intestine or small colon and block ingested feed and hay from moving. If left long enough, they will eventually cut off blood flow to the tissues as well.

Why these tumors occur isn't known, but they don't only occur in overweight equines. Colic from a strangulating lypoma cannot be managed with on-farm treatments like hand walking or medicating—surgical removal is the only remedy for this type of colic.

A horse with a strangulating lipoma may have only mild abdominal pain as the tumor grows. His pain will escalate as the tumor increases in weight, which causes the loop to tighten and block more ingested material. Eventually the blood supply to the tissue may be cut off, causing it to die.

The horse may initially appear restless, he may roll, paw or bite at his sides. Stretching out to ease the pull and sweating is not uncommon, nor is an elevated heart rate and depression. A horse with a strangulating lipoma most likely will not eat or pass manure. This form of colic may cause the horse to have a distended abdomen from the buildup of fluids.

This type of colic is diagnosed through observation of behavior, as well as through palpation of the small intestine, presence of abdominal distention and an increase in proteins and white blood cells in the peritoneal fluid.

The only treatment for a horse with a diagnosed strangulating lipoma is surgery, which will remove the tumor as well as any damaged intestine.

Study Shows Unique Equine Shoes Mimic Barefoot Benefits

A study out of Belgium sought to determine how medial-lateral heel movement in horses was affected by shoe configuration when compared to barefoot hooves. Drs. Brunsting, Dumoulin, Oosterlinck, Haspeslagh, Lefère and Pille worked eight Warmbloods on a treadmill at the walk, trot and canter for the study.

Barefoot hooves are flexible; they move with each step and have an elastic rebound as the horse moves off each hoof. This motion absorbs concussion and improves blood flow in limbs. Wearing shoes, however, restricts heel movement, limiting concussion absorption and blood flow.

All 16 forelimbs were tested. The hooves were either left barefoot, fitted with a conventional shoe or fitted with a split-toe shoe. The conventional shoe was a standard steel shoe with a toe clip. The split-toe shoe is a new shoe designed to enable heel expansion. The shoe has a toe clip and side clips between the second and third nail hole on each side. Once in place, the shoe is sawn through at the toe so the two halves of the shoe move independently of each other.

Typically, barefoot hooves expand during impact and midstance; heels contract during breakover. Heel expansion is greater at the trot and canter than at the walk, but heel contraction is consistent in all gaits.

The researchers found that conventional shoes restrict heel expansion by 36 percent compared to barefoot hooves. The team found no significant difference in heel expansion between hooves wearing split-toe shoes and barefoot hooves. They also noted that though shoes protect the hoof from excessive wear and can increase traction, that they can increase shock impact and weight on the distal limb. They conclude that the split-toe shoe provides advantages of both barefoot and shod hooves.