Page 99 - March_2022

Triple Vodka winning the TQHA Sale Futurity at Retama Park.
hind limb to be amputated, but his prosthesis allowed him to gallop in his paddock and breed like any other stallion.
Of course, the primary difference between equine and human amputation is that horses are required to be weight-bearing immediately after surgery. To solve this problem, Vlahos places two threaded pins in the distal third of the cannon bone and applies a transfixation cast – this allows the weight to be transferred to the pins instead of to the stump. A metal cup and strap system are utilized to reduce stress at the bone-pin interface when the horse pivots and turns.
The stump is checked for healing two to three weeks after the amputation, and the pins are removed approximately two weeks later to allow full loading of the horse’s weight on the stump through the cast. A couple more weeks go by, and the construction of the prosthesis can begin.
It takes multiple fittings and tests to ensure proper alignment of the carbon fiber prosthe- sis, which opens and closes with straps much like a ski boot to attach to the horse’s limb. The base is a titanium post and stainless steel foot- plate, with borium integrated into the bottom to increase traction.
The horse wears a standard human pros- thetic sock, and the sock is initially changed every day, and later every two to three days,
depending on the horse’s individual needs. The end result is a healthy, happy horse capable of life as a pasture pet or breeding animal.
Triple Vodka returned to Texas with his new prosthesis in January, and was able to be collected approximately a month later.
Of course, the horse’s gait is altered by the pro- cedure. Just like any horse with a fusion of a joint, other joints or parts of the body take up the load.
“Because they’ve lost range of motion, they appear stiff, mechani- cally, but they are comfortable,” said Vlahos. “The oldest horse we have right now is 15 years post-op, and he’s a very comfortable horse... We expect the horses to not really have any differ- ence in life expectancy.”
While Vlahos has not performed force plate analyses to determine the weight-bearing load on the sup- porting limb versus the amputated one, he notes that horses are able to pick up their good foot and fully weight bear on the prosthesis for farriery care.
Most equine amputations are performed at the fetlock level or below, but some have been performed at mid-cannon bone, and rarely at the mid-radius (above the knee or hock). In the latter case, the prosthesis
immobilizes the joint and requires a strap system similar to that of a high amputation in humans.
“It’s been a slow process to get it accepted, but the horses really do so well,” Vlahos said. “I’m pleased that other vets across the world are starting to recognize it as a viable option. When I’m helping other surgeons with the procedure, I routinely hear, ‘Why haven’t we been doing this before today?’”
Editor’s Note:
Triple Vodka (Tres Seis-Newport Lily, Stoli), who earned $224,670 while winning the TQHA Sale Futurity-G2 and Old South Derby, is the sire of six blacktype runners. The 2009 stallion is the property of and is standing at Zerlotti Genetics Ltd. in Pleasanton, Texas.
SPEEDHORSE March 2022 97
Coady Photography