For Life and Limb: Amputation
- Jun 1, 1996
It is a sight that sickens the toughest of horsemen. A magnificent Thoroughbred is reaching to the bottom of the well to summon up one last burst of speed as the wire approaches. Suddenly, the horse falters, then goes down, a portion of one leg dangling uselessly. Most think of only one solution--quick, humane euthanasia.
Unfortunately, it isn't just racing that can cause death-dealing catastrophic injuries. Jumping, eventing, cutting, and other equine sports where the horse is required to perform at speed, can also be causes. Then, of course, there is the matter of wire fences or cattle guards where a leg can become entangled.
While most horses which suffer catastrophic injuries are euthanized, there are a small number which have been saved through a process that is not that unusual in human medicine, but is rare when dealing with the equine--amputation.
There are a number of reasons that amputation surgery is rare in the equine world. For one thing, it is expensive. A successful amputation, complete with fitting a prosthesis, can run between $10,000 and $15,000.
Then there is the matter of the equine temperament. Every true racing fan knows the story of Ruffian, the magnificent filly who suffered a severe fracture in her match race with Foolish Pleasure. The leg was stabilized with surgery, but the high-strung filly fought off the best efforts of her human benefactors, causing irreparable damage to the injured leg, necessitating euthanasia.
There is also the matter of ongoing treatment. Unlike a number of other medical procedures, a horse doesn't simply recover from amputation surgery, get fitted with a prosthesis, then go about its merry way with no problems. The prosthesis must be removed and the stump cleaned on a regular basis for the rest of the horse's life.
One of the pioneers in equine amputation is Barrie Grant, DVM, MS, Dipl. ACAS, now co-owner of San Luis Rey Equine Center in California, but formerly head of the equine department in the College of Veterinary Medicine,Washington State University.
Correctly assessing a horse's personality, difficult though that may be, is key in the success of amputation surgery, Grant says.
"The adaptation to the loss of the support of one of their limbs, the use of a sling, becoming recumbent and rising with a leg in a full leg cast to either the elbow or the stifle, and intensive interaction with medical personnel requires a special personality," he explains. "It does not necessarily require a quiet, lovable horse who tolerates people and the administration of continued medications, but it does require the ability to adapt to rapidly changing stimuli in a calm, rational manner.
"It is difficult to predict what patients will do until the procedure has actually taken place. A patient who has already learned to sleep and rise with an injured limb in a cast or splint, who seems to enjoy human contact and is tolerant of injections, and who continues to have a good appetite and normal bowel movements should be able to undergo and recover from surgery without problems.
"We like to condition potential patients to a sling as we find that this often gives us an idea of their ability to adapt to new situations, and it also conditions them to the use of a sling during the initial recovery from anesthesia."
Grant also makes sure that owners of amputees don't have unrealistic expectations in the wake of surgery and fitting of a prosthesis.
"The owners," he says, "must be made very aware that their only expectations are that of a horse that can breed or conceive, deliver and nurse a healthy foal, and be able to ambulate in safe paddock conditions, often at a canter. But this horse should not be ridden, needs daily monitoring, every other day prosthesis changing, and a clean, safe area with protection from severe climatic conditions."
All of the foregoing concerning amputation sounds a bit negative, but, on closer analysis, it isn't.
If the horse that has a catastrophic breakdown or other injury that requires amputation to save its life, is a potential broodmare or breeding stallion of note, the expense might well be justified from strictly an economic viewpoint.
But, there is another aspect of horse ownership that overrides all of the economic considerations in the minds of some--love of the horse.
For Love of the Horse
A case in point is a young Missouri Fox Trotter stallion, owned by a family in Michigan. The 2-year-old colt got a rear leg caught and mutilated in high tension wire. The horse had not been broken to ride and was not in demand by the industry as a breeding stallion.
A local veterinarian advised that the animal be put down. The family declined the advice, believing there had to be another option. They learned about Ric Redden, DVM, owner of International Podiatry Center near Versailles, Ky., and shipped the horse to him.
Redden amputated the leg just below the hock, fitted the colt with a prosthesis, and some months later sent the horse home to Michigan. For that family, the expense and bother of caring for the horse are justified because they love the young animal and did not want him euthanized.
Redden has performed a number of equine amputations. One of his success stories involves a mare which makes her home in a paddock at his Central Kentucky facility. The mare was donated to Redden in 1993 with a life-threatening injury to her right rear leg. Redden performed an amputation and fitted the mare with a prosthesis. Today, she romps around her paddock with other horses, moving nimbly on her artificial leg.
About once a week, she is caught up, the prosthesis removed, the stump cleansed, fresh padding applied, and the artificial limb reattached.
Redden takes an idealistic approach when discussing amputations.
"I do not see this procedure as one that should be motivated primarily by economic gain," he says. "I see it as an option to euthanasia. To me, euthanasia isn't much of a choice."
Grant and a fellow veterinarian in New Mexico, Donna Harper, DVM, agree with that assessment and have taken an additional step. They, along with Joe Cannon, DVM, Grant's partner, have formed the Equine Heroes Foundation, which has as its primary goal the raising of money to help pay for equine amputations in cases where the owner does not have sufficient funds to do so.
Donations to the fledgling foundation are received at Equine Heroes Foundation, 1175 Chiquitos Road, Bosque Farms, N.M., 87068, and are used primarily to pay Grant's travel costs to perform
an approved amputation. Grant donates his time and expertise and picks up his own personal expenses.
While donations now arrive a few dollars at a time, the foundation has devised a plan that would net more proceeds and save more equine lives.
Harper explains it like this: At present, many valuable horses are euthanized because they are insured and euthanasia is a prerequisite for receiving an insurance payment. However, under the Foundation plan, the owner would agree to take less money if the horse could be saved via amputation. For example, if a championship-caliber horse were insured for $1 million, the owner would agree to accept $900,000, with $100,000 going to the Equine Heroes Foundation for amputation, a prosthesis, and post-operative care.
The balance of the $100,000 not used in surgery and post-operative expenses would go into the foundation coffers for horses whose owners don't have the money to pay for an amputation and prosthesis.
In the above scenario, if the horse recovers, it is returned to the owner, but with the foundation as something of a trustee to make certain the animal isn't abused.
Harper calls the plan a win-win approach. The horse's life is spared, and, in the case of a stallion or mare, the owner ultimately gets the horse back as a breeding animal. The goal now of the tiny foundation is to find an insurance company that will write such a policy.
Harper has had first-hand experience with amputees. She owns a mare that had a portion of her foot removed, but still functions very well as a broodmare.
The Amputation Procedure
In human medicine, says Grant, amputation is classified as one of the most painful of procedures.
"With horses," he says, "the degree of discomfort from the amputation is often much less than the actual conditions for which the surgery is indicated, as many patients who were non-weight bearing before surgery will support weight immediately after recovery and, in chronic cases, will even rest the contralateral limb."
When possible, Grant advises, it is wise to give the horse an opportunity to adjust to being placed in a sling prior to surgery as well as time to adjust to a cast or full limb splint. In some cases involving certain types of catastrophic injury, time is of the essence and this isn't possible.
The purpose of the sling is to help the horse to its feet after surgery and to prevent injury to the stump, as might happen if the horse immediately places too much weight on it.
Once the amputation surgery itself has been completed, the end of the operated leg is placed in a cast.
Grant explains that portion of the procedure this way:
"The distal portion of the operated leg is placed in a fiberglass cast that extends to as close to the elbow or stifle as possible. The use of a stockinette and padding is recommended. The cast should be thick enough to reduce the propagation of directed forces to the skin.
"After the stump has matured, the walking bar or temporary prosthesis is attached, using additional layers of the fiberglass material. It is important to measure the length of the opposite limb so that the walking bar can be applied in such a manner to make the operated leg the same length. The walking bar should be made to provide adequate ground surface for firm placement of the limb and reduce excessive torsion forces. Ideally, the materials used should be as light as possible, yet strong enough to withstand more than 15,000 pounds of torque."
The initial cast, says Grant, usually needs to be changed within the first week following surgery, especially if the limb was amputated with infection already present.
The second cast is applied in a manner similar to the first. Ideally, says Grant, this cast can be left on for three to four weeks. That gives enough time to construct a mold for construction of a prosthesis.
"A thin layer of fiberglass cast is then applied with only a stockinette for padding," Grant explains, "as this will be the positive mold. After the mold is cured, it is removed and another cast is applied. Hopefully, the prosthesis can be made and fitted no more than two weeks after the mold is prepared. The prosthesis is best applied for the first time under general anesthesia as it is often difficult to remove the cast without damaging the stump with the patient standing.
"Changes of the prosthesis are first done with the patient in a sling to avoid trauma to the stump end when the patient suddenly is aware that it does not have any support to the limb. After a few changing sessions, most patients adapt sufficiently to allow the prosthesis to be applied in a stall or even a pasture with the only distraction required being a generous serving of grain."
One of the primary problems to deal with in amputations is failure of the stump to heal properly if infection was present prior to surgery. (If there is no infection, healing of the stump often occurs quite rapidly.)
Another problem that can be just as deadly as improper healing of the stump is laminitis in the sound foot due to excess weight bearing on the opposite limb following surgery.
"The patients with long-term problems before amputation and those who failed to learn to lie down are most likely to develop rotation of the opposite coffin bone," Grant says. "The use of support shoes on the opposite limb, along with adequate bedding or shock-absorbing flooring will also assist in encouraging the use of the amputated limb and reducing the force on the contralateral limb."
One of Grant's success stories while at Washington State University had something of a bittersweet outcome. The patient was a top-notch Quarter Horse cutting horse stallion. The horse sustained a fracture in competition that necessitated leg amputation to save its life.
The owner did not have the money to pay for all of the costs of the surgery, so research funds from Oak Tree Racing Association were made available. Grant performed the surgery and the stallion recovered, with a bright breeding career ahead of him.
Unfortunately, he turned out to be sterile. Though he was fully capable of breeding by natural cover, no mares became pregnant.
While amputation today appears to be a viable alternative to euthanasia in some cases, there is still much to be learned about the procedure. There is also the need to develop a type of equine prosthesis that is even more efficient than those available today.
In order to gain some of that information, more amputation surgeries must be performed. In order for that to happen, a plan utilizing insurance funds, such as envisioned by the Equine Heroes Foundation, might have to be implemented.
About the Author
Les Sellnow is a free-lance writer based near Riverton, Wyo. He specializes in articles on equine research, and operates a ranch where he raises horses and livestock. He has authored several fiction and non-fiction books, including Understanding Equine Lameness and Understanding The Young Horse, published by Eclipse Press and available at www.exclusivelyequine.com or by calling 800/582-5604.
POLL: University Equine Hospitals