PennVet | New Bolton Center’s New Dynamic Endoscope Key to Diagnosing Upper Airway Problems in Horses
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New Bolton Center’s New Dynamic Endoscope Key to Diagnosing Upper Airway Problems in Horses

By: Louisa Shepard Published: Apr 23, 2015

The athletic Thoroughbred gelding might have had a slight “roar” to his breathing when event rider Lara Geiger purchased Benji four years ago; but if it was there, it was hardly noticeable.

As each year passed, the raspy breathing became more and more pronounced. In the past few months, the condition worsened. “It sounded like he was gasping for air,” Geiger said.

Dr. David Levine and owner Lara Geiger place the dynamic endoscope on Benji's head and saddle.

Many horses with these symptoms, known as “roarers,” come to New Bolton Center for diagnosis and treatment. Now our clinicians have a new “over-ground, dynamic” endoscope to help diagnose this and other upper-airway conditions.

The endoscopy equipment straps right onto the saddle and around the horse’s head, wirelessly connecting to a portable monitor, so veterinarians can see inside the throat, and record the video, while the horse is exercising.

“We expect the dynamic scope will be an important tool for the diagnosis of upper airway disease, and a possible alternative to treadmill examination,” said Dr. Barbara Dallap Schaer, New Bolton Center Medical Director.

Our veterinarians can travel to examine horses on their own turf with the new endoscope, at stables, racetracks, or training centers. Alternatively, horses can come to New Bolton Center for examination in the hospital’s indoor arena.

Bringing Benji to New Bolton

Dr. Chris Uhlinger, a former New Bolton Center Field Service veterinarian, was concerned that there might be more than one cause to Benji’s condition. She made the referral to Dr. Eric Parente, New Bolton Center surgeon and a specialist in equine upper airways, and accompanied Geiger on the seven-hour trailer ride from North Carolina. 

“Dr. Parente is the master of horse throats,” Geiger said in a recent interview. “He was very helpful, very informative.”

Lara Geiger rides Benji during the endoscopic examination.

Parente decided to use the new endoscope, in part because Benji’s breathing problems were most acute while he was being ridden.

“The main advantage of dynamic, over-ground endoscopy is that we can examine the horse with the head and neck in the positions used while riding,” Parente said. “Because we know that head and neck position can accentuate or cause an abnormality, we sometimes need to reproduce that exact positioning while examining the horse.”

On the treadmill, horses usually have an extended or relaxed neck position, but riding horses usually have their heads “collected” or tucked in to some degree. While a thorough standing endoscopic examination can provide an answer in many cases, in some cases examination during exercise is essential.

“The use of a dynamic over the ground endoscopy is one of those technologies, like digital radiographs, that will transform equine diagnostics,” said Dr Uhlinger, who is in private practice in North Carolina. “It will be a game-changer.”

Using the Dynamic Endoscope 

For Benji’s case, Parente teamed up with Dr. David Levine, Staff Surgeon, who is one of three clinicians at New Bolton Center who will perform dynamic endoscope examinations.

Levine and his team positioned the endoscope equipment on Benji, and then Geiger rode him for about half an hour at walk, trot, and canter, in New Bolton Center’s Equine Performance Evaluation Facility arena.

The portable monitor shows video of the inside of Benji's throat.

“Benji was really good and he didn’t seem bothered by it at all,” Geiger said. “It was a good experience for both of us. That is a beautiful indoor arena. The setting is fantastic.”

While she was riding, the veterinarians were closely observing Benji, but also watching live video of the inside of his throat on the portable monitor.

What was clear to Parente was that the left flap on the sides of the larynx, the arytenoid, was not opening fully during exercise, which was causing the noise.

Caused by degeneration of the laryngeal nerve, the condition, laryngeal hemiplegia, typically results in the left arytenoid being unable to open fully, and even collapse, Parente said.

“Every time a horse breathes, the air sucks across the opening. The narrower the opening, the higher pitched the noise becomes,” Parente said, noting that the condition is worsened by exercise or fatigue.

The endoscope was also useful to investigate whether there were any other problems. Uhlinger was concerned that Benji would displace, or “flip,” his palate over his epiglottis, which did not happen during the exam.

“Benji came in for roaring and possible displaced palate. The dynamic endoscope helped sort that out,” Uhlinger said.

A Special Tie Back Surgery

The remedy for laryngeal hemiplegia is laryngoplasty or “tie back” surgery. Parente performed a unique version of tie back surgery that he modified about 10 years ago, on Benji on March 31.

At left, Dr. Eric Parente, assisted by an intern and student, remedies Benji's laryngeal hemiplegia with a laryngoplasty or “tie back” surgery.

The arytenoids, or flaps, on each side of the throat, work like French doors to open and close, with a hinge, or joint, at the base. Traditional tie back surgery sutures them to keep them open permanently at 80 or 90 percent. Parente’s tie back surgery eventually fuses the joint so they stay open on their own.

Parente said the surgery is common, one that he performs on more than half of his patients. “The horse can still swallow normally and get enough air,” he said.

Geiger said Benji came through the surgery well, and he is recovering, on stall rest and hand walking for about a month. He must eat everything from ground level to reduce coughing during the recovery time. “He’s been a good patient so far,” she said.

Details of the Dynamic Endoscope at New Bolton Center

In addition to Levine, the other New Bolton Center clinicians who will perform dynamic endoscope examinations are Dr. Elizabeth Davidson, Associate Professor of Sports Medicine; and Dr. Meagan Smith, Staff Veterinarian in equine Field Service.

The price, not including travel, is $550 to conduct the exam and provide a report. Trip fees can be shared for multiple horses evaluated at one facility. Patients that receive this evaluation by New Bolton Center clinicians and require surgery for the diagnosed condition will receive a 5% discount for that hospital visit.