Bridle-like device that holds larynx in proper position might be alternative to surgery

by Bill Heller

SCIENTIFIC discovery knows no boundaries. Norm Ducharme, D.V.M., M.Sc., a professor of surgery and medical director at Cornell University's Equine Hospital, had been studying dorsal displacement of the soft palate (DDSP) in horses for years before he isolated the muscle that he thought was responsible for causing the condition, the thyrohyoid. That led him to a hypothesis.

"I'll tell you the truth, my hypothesis was that if I cut that muscle and a couple others, that would stop the displacement," said Ducharme. "And it did the exact opposite. It created the displacement. I was 100% wrong."

That revelation led him to discover that if he held his finger in the back of the bone in the throatlatch area of a horse with DDSP, he could manually move the voice box upward above the larynx and stop the displacement.

"It surprised me," Ducharme said. "It was probably like discovering penicillin by leaving fungus on your coffee cup."

In 2002, Ducharme and his Cornell colleagues, Brett Woodie, D.V.M., M.S., (now a surgeon at Rood & Riddle Equine Hospital in Lexington) and Richard Hackett, D.V.M., M.S., rigged a device to keep the horse's voice box fixed in that position and then tested seven horses with DDSP while they were exercising on a treadmill. The device, dubbed the Cornell Collar, stopped DDSP in six of the seven horses.

They reported the results of the study in an article in the September 2005 edition of the Equine Veterinary Journal. By then, the Cornell Collar had been patented and was in limited use by trainers who embraced the idea of using a nonsurgical approach to solve a common problem, one evidenced by the 85% to 90% of racehorses that wear tongue ties to help prevent upper airway obstruction.

Racetrack study

DDSP occurs when horses breathe heavily and their soft palate (the rear roof of the mouth) moves up and over the epiglottis, partially obstructing the airway.

"Palate displacement is similar to sleep apnea, snoring in people, where the palate billows in the airway and obstructs the airway during exhalation," Ducharme said. "The horse is trying to get the air out. That's why you hear the gurgling noise. About 20% of horses are silent displacers because they don't make a noise. In young racehorses, it's more of a problem than older horses.

"The young horses have more inflammation in their upper airways. If there's inflammation in the airways, the muscles in the palate don't function as well. If that happens, they can't resist the pressure changes from the horse inhaling and exhaling. The palate in horses needs to be underneath the voice box [larynx]. Surgery and the collar is a way to position the voice box forward and upper, which prevents or minimizes the likelihood of the obstruction."

But, obviously, a study of seven horses with DDSP at Cornell was not sufficient to move forward. So Ducharme and his colleagues, using a grant from Cornell's Harry M. Zweig Memorial Fund for Equine Research, conducted a ten-month field study on Thoroughbreds training at the New York Racing Association's three racetracks, Aqueduct, Belmont Park, and Saratoga Race Course, from April 7, 2003, through February 2, 2004.

"The problem was we couldn't use it during racing," Ducharme said. "We could only use it in the morning while the horse was training [which is less strenuous than racing]. We tried 46 horses that their vets and trainers thought were displacers. All those 46 worked out over a period of months. There were only 12 that displaced in the morning. Of the 12, it worked on eight, made no difference in two, and made it worse for the other two."

Gary Contessa was one of several New York trainers who participated in the study.

"My first thought was that NYRA is never going to allow this," Contessa said. "They wouldn't allow us to use nasal strips. How are they going to let them run with this?"

Contessa participated anyway.

"I had four horses I knew who were displacing their palates," the trainer said. "The first few days, they didn't like it [the collar]. Once they got used to going with it, they held their head level, traveled well, and breathed better. I used it for about three months. I saw some degrees of improvement. I think it would be a good thing."

So did Cornell.

With the backing of the university, Ducharme, Woodie, and Hackett patented the Cornell Collar in 2004, and it is already being used sporadically by Standardbred trainers in the United States, Canada, Europe, Australia, and New Zealand, and by Thoroughbred trainers at Calder Race Course in Florida and at Northlands Park and Stampede Park in Alberta. In Pennsylvania, Standardbreds are allowed to use the collar, but it is banned for Thoroughbreds. No request has been made yet to allow horses in New York to wear the collar in races.

Commissions split

The collar fits on like a bridle, with the head strap resting in front of a horse's ears and a lifting mechanism placed midline between the jaws. It is connected by a head-strap buckle.

Some horsemen in Canada have been using the collar since it went on the market in 2004 at a cost of $400 to $500. The collar is available from Vet-Aire (www.vet-aire.com).

"For harness racing, it's been in use here for a couple years; we allowed them this year for Thoroughbreds for the first time in Alberta," Jason Teague, the assistant race secretary at Northlands, said in December. "I've seen it many times here."

He said information about horses that wear the collar is indicated in the track program.

"I keep track of it manually," Teague said. "I'm the horse identifier and equipment judge."

In Pennsylvania, Lawrence Soma, V.M.D., professor of anesthesia at the University of Pennsylvania's New Bolton Center, made a presentation about the Cornell Collar at the February 16, 2005, meeting of the Pennsylvania State Horse Racing Commission. After discussion, a motion was passed unanimously to ban the collar and "any similar device" from all Thoroughbred tracks in Pennsylvania.

"I showed them a film, and we just discussed it, and they decided to ban it," Soma said in mid-December. "I'm not quite sure why. I just presented the pros and cons."

The cons included fear that misuse of the collar could precipitate cheating.

But there must have been hidden pros, however, for the Pennsylvania Harness Racing Commission approved use of the collar at its March 22, 2005, meeting.

"When we heard about it, some of our horsemen were already using it," said Anton Leppler, the commission's executive secretary. "It works if it is put on properly. That was the concern we had, that the trainer or the vet who puts it on puts it on correctly, otherwise it may impede the horse's breathing."

Calder okays collar

In September 2005, Calder approved the use of the Cornell Collar under strict guidelines, which requires a trainer to present a letter from an attending veterinarian that certifies she or he believes the collar is an appropriate device for that particular horse and that the horse should continue to use it after the first time.

Mary Scollay, D.V.M., senior association veterinarian at Calder and Gulfstream Park, had seen one of Ducharme's presentations about the collar.

"I thought it was very impressive," Scollay said. "I was aware that they were allowing it in New York for training, but not for racing. It may be more in use than people are aware.

"I felt that Norm's research was credible," she continued. "I, and a lot of others, wondered if it could be worn incorrectly or not used sometimes. On the treadmill, I am positive it works. In a racing environment, I'm more guarded in my optimism. The fit is key to its efficacy. But a Figure-8 [bridle] could be put on incorrectly. A saddle can slip.

"I recommended to management that I felt, based on the research Norm showed us, that it was a legitimate device that could be useful in addressing a condition that many racehorses have: upper airway problems."

Calder's paddock judge, John Breen, was given the responsibility of inspecting the collar every time a horse wears it in a race. "It's no big deal," Breen said.

Through mid-December, only one horse was identified to be wearing it improperly before loading into the starting gate. "They took off the collar and he won anyway," Breen said.

Through mid-December, four Calder trainers were using the collar. One is Henry Collazo, who has 40 horses at Calder, ten at Tampa Bay Downs, and another dozen on a farm.

"A lot of horses have throat problems," Collazo said. "For this particular situation, I have half a dozen horses. There [are] all different kinds of ways to treat it. I'm from the school of, 'I don't know; I can learn.' My mind is open. As long as it's not invasive with surgery or chemicals, I'm more than interested.

"I looked them up on their website," Collazo added. "I called them up. It's a small price to pay for something that works. On some horses it does work. It changes the way the epiglottis fits on the palate. It puts it in a more normal position and it gives them an opportunity to be the best they can be. The animal comes first."

Another Calder trainer who has used the collar is Jim Chapman. He used it on a two-year-old filly he said "was displacing so badly it was scaring her. It frightened her. She started refusing to go to the track."

Chapman gave his filly time off and added the collar when she resumed training. "We seem to be doing better with her," Chapman said. "I think it helps. I think part of the deal is that someone is going to have to be pretty on the ball to set this up right."

Change of equipment?

At Calder, information about the collar is not included in Daily Racing Form or in the track program. "We had a long discussion about it because it is a change of equipment, but there hasn't been a great demand for that, and I haven't seen any form reversal in horses wearing it," Scollay said.

Collazo pointed out, "In a way, it should be [put in the program] because it would be like blinkers. They used to put nasal strips in the program and in the Form. But they don't put down whether the horse had his tongue tied. They don't tell you if there is a shadow roll, or what kind of blinkers, or what kind of bit. And they don't tell you what kind of medication."

Although questions remain, horses with DDSP now have another nonsurgical option to alleviate the problem.

Bill Heller, winner of the 1997 Eclipse Award for outstanding magazine writing, is a New York correspondent for Thoroughbred Times.