Tag: Horse Care

Three-Legged Quarter Horse Stallion Thriving With New Prosthesis

When Quarter Horse stallion Triple Vodka developed a septic coffin joint in 2021, Texas-based breeding farm Zerlotti Genetics had to terminate the multiple stakes winner's breeding season early. Despite top-notch care, the debilitating issue worsened over the course of the year, and eventually became so serious that only two options remained.

Either Triple Vodka would have to be euthanized, or he could be sent to Wyoming's Yellowstone Equine Hospital to meet Dr. Ted Vlahos.

Vlahos has become an industry pioneer in equine limb amputation and prosthetics, completing over 100 cases across four continents. Amputation is a last-ditch effort to preserve a horse's life, Vlahos explained, and he only performs the procedure under strict circumstances.

“Our premise is that we much prefer that a horse have four legs than three, but in cases where we can't save the leg, we are able to save the horse,” Vlahos said. “We deal with the most severely injured horses in the world. We get the worst of the worst, so we're eliminating that source of pain and disease.

“The procedure is well-tolerated by the horse and they can do very well, but it's not for everyone. We thoroughly interview clients to be sure they're fully committed, and that their horses are good candidates for it.”

Another consideration is whether laminitis has already progressed in the horse's supporting limb. Initially, Vlahos and his team avoided cases with any signs of support limb laminitis, but after 22 years of performing the procedure they have documented mild cases resolving after removal of the damaged limb and addition of a prosthetic.

Triple Vodka's easy-going demeanor made him an ideal candidate for the procedure, and the stallion was shipped to Wyoming in the fall of 2021.

Since Triple Vodka's issue was in the coffin joint within the hoof, his right front leg was amputated below the fetlock. 

“In the case of the distal limb, we preserve the sesamoid bones so we have a bulbous end,” Vlahos explained. “We also don't want horses to walk on raw nerve endings on that stump, so we perform a neurectomy removing about three inches of nerve so they can't feel the stump. We also perform a tendon flap procedure, creating a thick pad of tendon at the end of the bone that is then covered with skin.”

Both the neurectomy and the tendon flap procedure are well-described in human medicine, a fact Vlahos certainly appreciates due to his incorporation of the expertise of human trauma surgeons into his practice. Vlahos hired Dr. Dale Larson, a cardiothoracic surgeon with experience in Vietnam, for three years as his assistant to learn about modalities that could be adapted to equine medicine, and he has worked with four other human surgeons to perfect his techniques.

Vlahos looks back to his early schooling at Ohio State as one of the motivating factors in pursuing amputation and prosthetics as an equine specialty.

“I had a pretty famous professor at the time who told us, 'Never be afraid to fail,'” said Vlahos. “That was Dr. Larry Bramlage, and he'd just published his first group of fetlock arthrodesis horses. I took that to heart and was fortunate to be trained by wonderful human surgeons who saw the worst of the worst in Vietnam. They helped me with my desire to advance our profession and help the horse successfully.”

Vlahos' mentor at Washington State, Dr. Barrie Grant, also performed several successful amputations on prominent equines, including a Thoroughbred stallion named Boitron. He had suffered a hauling accident that required a 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 prosthesis, 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 footplate, with borium integrated into the bottom to increase traction. 

The horse wears a standard human prosthetic 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 procedure. 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, mechanically, 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 difference in life expectancy.” 

While Vlahos has not performed force plate analyses to determine the weight-bearing load on the supporting 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?'”

Source of original post

Double Down: Traditional Deworming Increases Drug Resistance At Alarming Rate 

Traditional deworming methods dictate that all horses on a farm be dewormed with moxidectin or ivermectin at specific intervals, usually every other month or quarterly. Though significantly easier on farm managers, this method increases anthelmintic resistance two to three times more rapidly than other deworming programs, reports The Horse.

Dr. Thomas Geruden, with Zoetis in Belgium, said these results are not surprising as the worm population is continuously pressured for selection of survivable genes in the calendar-based deworming routine.

Geurden and other researchers in Belgium, along with scientists at the Gluck Equine Research Center in Lexington, Ky., studied two farms that utilized the standard deworming protocol on their Belgian draft horses.

The deworming schedule should have corresponded with the timeline of worm egg development, but drug resistance has caused the worm eggs to appear twice as fast as expected.

Fecal egg counts on every horse on the farm were performed every two weeks from April to September for three years. Horses that had more than 250 eggs per gram of manure were given pyrantel embonate, an alternative dewormer. All other horses were treated with standard anthelmintics in the spring and fall, reducing their deworming by half or two-thirds.

The researchers used the fecal egg counts, both before and after treatment, to create a model of worm life cycles that could predict drug resistance over the next 40 years. The team found that the alternative dewormer maintained low egg counts in all horses and slowed drug resistance in worms by 200 to 300 percent.

The scientists also found that the horses considered “high shedders” of worms were almost always under 5 years old. This knowledge might allow horse owners and caretakers to target which horses may need fecal egg counts run more often – and which may need more-frequent treatments.

[Story Continues Below]

The data suggests that fecal samples should be gathered for egg counts between 42 and 56 days after the spring moxidectin/ivermectin treatment, with a second sample taken between days 98 and 112. These numbers will help determine future egg counts and reduce deworming frequency.

The ability to model the rate of anthelmintic resistance using different deworming protocols has been helpful when discussing deworming with both horse owners and vets, the researchers found. A deworming plan specifically tailored to a farm may be more expensive initially, but the less-frequent, targeted deworming will pay off financially in the long run as dewormer resistance slows.

Read more at The Horse.

Source of original post

Study Suggests Dangerous Behavior Could Be Caused By Skeletal Pain

Horses that exhibit undesirable behaviors like bolting, rearing or kicking under saddle are often assumed to have poor training or to simply be ill-tempered, but a new study shows that horses acting progressively more dangerously may be reacting to axial skeletal pain.

Dr. Melissa Story studied 14 horses that had exhibited increasingly dangerous behavior, putting their riders' safety at risk, and had subsequently been euthanized.

She and her research team performed spinal exams, gait evaluations, diagnostic imaging, neurologic evaluations, and pathologic and histopathologic exams of the axial skeleton (the skull, the rib cage, and the backbone).

Those evaluations, along with prior medical records, owner and trainer complaints, and an exam completed once the horses had been euthanized, allowed the scientists to tentatively determine that skeletal pain may have been to blame for the horses' behavior.

Ten horses showed severe behavioral responses during both the mobilization and myofascial exams. The most common areas of concern were the lumbosacral and cervicothoracic regions. Additionally, 71 percent of study horses had hemorrhage or hematomas in these areas.

The scientists concluded that structural pain (neuropathic) was the root cause of the dangerous behavior. They noted that ganglia relay peripheral sensory information to the central nervous system and that ganglionitis has been associated with neuropathic pain syndromes. More research is needed.

Read more at Veterinary 33. 

Source of original post

Storage A Concern When Feeding Corn On The Cob

Question: A fellow boarder was feeding her horse ears of field corn one evening. The kernels were hard and a deep golden color. I asked her if this was from this year's planting, and she said it was from an old corncrib that was on a relative's farm. Is this a safe practice?

Kentucky Equine Research responds: Feeding corn to the horse is not an issue, as it is often an ingredient in high-quality, well-formulated feeds. The concern involves where the corn was stored and for what duration it was there.

Corncribs are relics on most farms these days. Usually fashioned from wood, they were once commonplace on farms. The walls of the corncribs were typically not entire, purposely left open to allow air to circulate throughout. While ventilating the corncribs was essential for keeping the corn dry, the openness often allowed rodents and other vermin to gain access.

If ear corn becomes wet during storage in a corncrib, there is a chance that mold will develop. Unlike cattle, horses are extremely sensitive to mold. This is evident in the difference in hay that can be fed to the two species; generally cattle can tolerate more dust and mold than horses can.

If a horse consumes corn contaminated with toxins produced by Fusarium spp., it might be at risk for moldy corn poisoning, also known as equine leukoencephalomalacia. This disease progresses quickly in most animals with death occurring within a few days. Clinical signs of the disease include anorexia, lethargy, and a roster of neurological deficits: staggering, circling, head-pressing, and inability to swallow.

[Story Continues Below]

Though this is not a common disease, it is a deadly one and there have been numerous outbreaks recorded throughout the United States. Cases seem to pop up in late fall through early spring and are especially prevalent when a dry growing season is followed by a rainy fall.

While contaminated kernels might be off-colored, there is no definitive way to tell if corn is infected with the disease-causing fungus by visual inspection. Corn screenings, a by-product of corn handling and processing that contain, among other things, whole and partial kernels of corn, are another likely source of contamination.

The best way to prevent a case of moldy corn poisoning is to provide horses with a professionally formulated and manufactured concentrate that is appropriate for age and lifestyle. When fed by itself as a concentrate, corn does not supply adequate nutrients for optimal health.

The temptation to give horses treats is a great one, but I'd stick with more traditional ones: apples, carrots, or an occasional alfalfa cube.

Read more here.

Reprinted courtesy of Kentucky Equine Research. Visit ker.com for the latest in equine nutrition and management, and subscribe to Equinews to receive these articles directly.

Source of original post

Verified by MonsterInsights