Modern casts for horses are lightweight, durable, and sometimes removable

by Denise Steffanus

UNLIKE EARLIER days in veterinary medicine, horses with severe leg injuries are no longer considered to be hopeless cases, so a horse wearing a cast is not an unusual sight.

A cast is used as a first-aid tool to support and protect an injured limb until a veterinarian arrives or during transport to a veterinary clinic; to immobilize a limb while it heals from surgery or injury; to provide support during healing so the horse can stand and walk; to reduce concussion on an injured limb; and as added support to a fractured limb that has been repaired using screws or plates. Casts sometimes are used to correct leg deformities in young foals to help them grow straight and strong.

Modern equine casts typically are made of fiberglass, which, unlike old plaster casts, are lightweight and do not degrade when exposed to moisture. A fiberglass cast provides rigid support to the limb during healing.

Most fiberglass casts are premanufactured. After selecting the appropriate size for the patient, the surgeon tailors the fit to the individual by using the appropriate amount of bandaging underneath it.

Removable bandage cast

For some injuries to the limb, such as those involving soft tissue or where wounds or surgical incisions exist, the veterinarian needs to be able to remove the cast frequently to treat the area and change the bandage. A removable cast made of bandaging material and covered with fiberglass is ideal for this purpose.

"Case selection is very important when deciding if a bandage cast has advantages for some case management over traditional casting methods," noted Patty Hogan, V.M.D., the New Jersey surgeon who saved champion Smarty Jones's life after he was injured in a starting-gate accident as a two-year-old. "If instability of the lower limb exists, it is imperative that the horse can comfortably and safely stand during the bandage changes without compromising the integrity of the repair."

A cast typically is applied while the horse remains under general anesthesia after a surgical procedure to repair the injured limb. First, the surgeon wraps the limb with a light, sterile dressing of conforming gauze. Two or three pieces of thin cotton sheeting are rolled tightly over the sterile dressing and around the foot, and then secured with brown gauze and latex bandaging tape (Vetrap, Co-Flex).

Next, the surgeon places a strip of orthopedic felt around the cannon bone and covers that with a roll of casting foam, then begins to roll layers of fiberglass casting material over the limb, including the foot, and reinforces the bottom of the foot, which must be able to withstand abrasion.

Like a traditional fiberglass cast, the bandage cast provides rigid support, but it can be removed, as needed, to treat the underlying limb. The same cast can be reapplied afterward.

The cast is removed by cutting it vertically on the inside and outside of the limb, while leaving the foot piece intact. The horse's foot then is lifted out of the cast for treatment. After tending, the veterinarian wraps the limb with fresh bandage and places it back in the cast, which is fitted back together and wrapped securely with tape.

"For management of soft-tissue injuries in our practice, the bandage cast has been a very useful adjunct in the treatment of extensor and flexor tendon lacerations, open wounds of the fetlock and pastern joints, severe run-down lacerations, and large, chronic granulating wounds," Hogan reported. "Orthopedic injuries managed with a bandage cast include fetlock joint subluxations, several cases of internal fixation that required regular wound care, and two cases of previously repaired cannon bone fractures that subsequently became unstable in the postoperative period."

Red flags

While your horse is wearing a cast, it is important to check on him several times a day and take his temperature each morning and evening. If the horse has a fever (more than 101¡), he could be developing an infection, and you should notify your veterinarian immediately.

Pay particular attention to the cast area. A foul-smelling discharge from beneath the cast, swelling above or below it, or noticeable heat emanating from it also may indicate infection and the need for immediate veterinary care. Other warning signs that a problem may exist are increased pain, lack of appetite, depression, and excessive lying down.

Anyone who has ever worn a cast knows that the itching underneath the cast can be maddening. Humans often resort (against doctor's orders) to inserting an unbent wire hanger under a cast to scratch. Horses chew at a cast to alleviate itching and might damage it enough to necessitate its replacement. But chewing also could indicate the limb underneath is irritated and in need of immediate attention.

Damage to the cast may result if your horse is rambunctious or if he is determined to remove the cumbersome object. If the cast is broken or damaged, notify your veterinarian, who will repair or replace it.

Cast care

A cast should be kept clean and dry to minimize the chance of a horse acquiring an infection underneath it and to extend the life of the cast. A horse wearing a cast should be confined to a stall that is kept scrupulously clean. Wrap the cast openings lightly but securely with bandaging tape to keep out debris, and change the tape regularly as it becomes soiled. If the cast becomes damaged, excessively dirty, or wet, contact your veterinarian, who may repair or replace it if it cannot be restored to good condition.

A horse wearing a cast should not be loaded on a trailer unless your veterinarian advises you do to so.