The technology surrounding equine fracture repair has evolved tremendously over the past decade. Surgeons can now repair many fractures previously deemed unfixable, often with a relatively good outcome for both survival and athletic function.
Nevertheless, said Denis Verwilghen, DVM, MSc, PhD, DES, Dipl. ECVS, associate professor of Large Animal Surgery at Denmark’s University of Copenhagen, long bone fractures remain challenging to treat, and the chances of returning to full athletic activity can be limited.
“These types of surgery further demand for specialized infrastructure, dedicated and experienced personnel, and the use of expensive equipment involving plates and screws generally rendering the cost of treatment being high,” he explained. “Many horse owners would, therefore, generally opt out of fracture treatment for their beloved horse due to financial reasons.”
But there’s some good news for owners of smaller equids, such as donkeys, ponies, and Miniature and other small horses. Verwilghen and colleagues have determined that using a ring-shaped splint and a cast in some lighter-weight animals can result in good healing and pasture soundness or, rarely, a return to athletic activity, at about a third of the cost.
A modified Thomas splint-cast combination (MTSCC) provides an effective way to relieve weight-bearing in a fractured limb to allow a small equid’s bone to heal without surgical intervention (in many, but not all, fracture types). After an average of 10 weeks of MTSCC placement, the animals can live pain-free at pasture, said Verwilghen.
Verwilghen and colleagues examined the medical records of 13 ponies, donkeys, and small horses that had been treated for long bone fractures using MTSCC at the University of Liège Equine Clinic, in Belgium, from 2001 to 2012. Affected bones included the tibial diaphysis (growth plate of the tibia, the bone above the hock), the ulna (a bone in the horse’s forearm), the distal metatarsus (lower hind cannon bone), the proximal metacarpus (upper front cannon bone), the radial diaphysis (radius, another long forearm bone), the calcaneus (the heel bone), and the distal femoral physis (the growth plate of the lower part of the femur, the bone just above the stifle).
The researchers contacted 12 of the owners (one couldn’t be located) six months to several years after hospital discharge to check on their animals’ statuses.
They found that eight of the equids (67%) had recovered from their fractures and had become pasture sound, Verwilghen said. Six of these pasture-sound horses had developed some sort of “obvious” deformation at the fracture site, such as bony swelling or an angular deviation, he added.
One horse—a Quarter Horse that had fractured her ulna at 12 days old—went on to working at a competition level, he said.
The remaining three equids, however, were euthanized due to subsequent fractures (in two cases) or colitis (in one case).
Verwilghen noted that some of the animals might have had better outcomes if they had undergone surgical fixation treatment. But, often for financial reasons, this just wasn’t an option for the owners. Other owners might have chosen this simpler technique because the animal wasn’t intended for athletic activity anyway, he added. In all the cases, the owners had accepted the fact that the MTSCC was to be considered a “salvage” procedure—meaning it would keep the equid alive and pain-free, but most likely unrideable.
“It’s a trade-off,” Verwilghen said. “It’s a less-costly treatment that has a good outcome, which is a good alternative to just (euthanizing) the animal because there are no finances to do the top-level treatment.”
In the cases in their study, the expense of the “top-level treatment” would have been significant, he added. “All the fractures were pretty bad and would have necessitated a lot of metal implants and surgical time and aftercare,” he said. “So the costs would have been dramatically increased in the case of internal fixation.”
Unfortunately, the MTSCC procedure is limited by the weight of the animal (the researchers estimate horses weighing less than 300 kilograms, roughly 660 pounds, could be candidates), so it’s not useful for full-size horses. But, it still affords lighter-weight animals a chance to recover from fractures in a welfare-friendly fashion, said Verwilghen.
“When an animal is pasture-sound, this means he is considered to be able to live happily and without pain or with a minimal amount of discomfort that is considered ethically correct in a pasture condition,” he said. “If he jumps around he might be in a little bit of pain, but he won’t have pain or discomfort if he’s just doing his usual activities. But that does mean you’re not meant to ride him or compete with him (except in unusual circumstances and with veterinary approval).”
The study, “Modified Thomas splint-cast combination for the management of limb fractures in small equids," was published in Veterinary Surgery.