Equine medical center faculty member performs life-saving surgery on Smithsonian National Zoo's zebra

A faculty member at Virginia Tech's Marion duPont Scott Equine Medical Center recently lent assistance to the Smithsonian National Zoological Park when one of its two zebras became ill with a life-threatening case of colic.

On Monday, August 27, Dr. Jennifer Brown, clinical assistant professor in emergency care and equine surgery at the Marion duPont Scott Equine Medical Center, performed an operation on the two-year-old male Grevy’s zebra named Dante at the Smithsonian’s onsite veterinary hospital in the District of Columbia.

The zoo’s veterinarians were first alerted to a problem by Dante’s keepers who contacted them on the morning of Sunday, August 26.

“Any time that one of these animals is sick, it is pretty challenging because, as prey animals, they tend to hide pain,” said Dr. Carlos Sanchez, associate veterinarian at the National Zoo. “Dante’s keepers said that he seemed really depressed. His coat was darker on one side suggesting that he had been lying down for an extended period of time during the night and he was just not acting like himself.”

A dart was used to anesthetize the zebra and a diagnostic examination for colic was performed.

“The main difference between zebras and domestic horses is that you can’t approach zebras without sedating or anesthetizing them because they are dangerous animals that can hurt you pretty bad,” said Sanchez. “We have to anesthetize them even to get a blood sample or heart rate, and, in this case, to perform a colic exam.”

Mineral oil was administered through a nasogastric tube and intravenous fluids through a catheter placed on the zebra’s jugular vein in order to correct dehydration and soften blockages in the intestines which are a common cause of colic.

“We expected that the mineral oil and other treatments would do the job,” said Sanchez. “Dante was monitored closely for the remainder of the day and looked better but not as good as we would have expected so we started to consider surgical treatments. On Monday, we decided to contact the Equine Medical Center’s team about helping with the surgery since they specialize in treating this type of condition.”

According to zoo officials, its highly trained veterinary staff is occasionally supplemented with outside experts.

“We have a really talented multi-faceted staff at the zoo and one of the great things about them is that they have a network of experts to call upon,” said John Gibbons, spokesperson for the National Zoo. “The expertise that we have here is enhanced through the use of outside specialists, like the equine medical center’s doctors, when needed.”

When Brown received the call from Dr. Suzan Murray, chief veterinarian at National Zoo, she knew that the situation was dire.

“Dante was experiencing moderate colic,” said Brown. “Systemically he was stable but it was a critical situation.”

As a condition that frequently afflicts horses, colic is one of the Marion duPont Scott Equine Medical Center’s most commonly treated emergencies with almost 250 such cases having been seen at the center from July 2005 to June 2006. Zebras are members of the Equidae or equine family and therefore have digestive systems that are also susceptible to the disease.

“Although our faculty members primarily treat domesticated horses, they are fully equipped to treat all members of the Equidae family,” said Dr. Nat White, Jean Ellen Shehan Professor and Director of the Marion duPont Scott Equine Medical Center. “We treat donkeys and mules and the occasional exotic species.”

Like a horse, a zebra’s digestive system consists of intestines that stretch from eleven to twelve times its body length, all of which can be easily affected by external factors including changes in diet or exercise. For Brown, who has performed hundreds of colic surgeries on horses, having a patient with stripes was highly unusual but technically very similar.

“Once they covered his stripes up with my drape, I couldn’t tell the difference between him and a horse,” said Brown. “They have almost the same gastrointestinal tract although colic is fairly uncommon among zebras.”

A medical team including Brown, surgery resident Sam Hart, licensed veterinary technician Tina Cooman and fourth year veterinary student Samantha Baglin, traveled from Leesburg to the zoo in Washington to conduct the surgery. National Zoo staff attending Dante’s procedure included Dr. Suzan Murray, chief veterinarian; Dr. Carlos Sanchez, associate veterinarian; Dr. Luis Padilla, associate veterinarian; Dr. Katherine Hope, zoo medicine resident; Lisa Ware, veterinary technician; and Kim Williams, licensed veterinary technician.

“We brought down some of our equipment because we didn’t know what they would have but the zoo’s hospital was very well equipped for this,” said Brown.

The 605-pound zebra was already under anesthesia having been sedated by the zoo’s veterinarians before the Marion duPont Scott Equine Medical Center’s medical team arrived.

“Another difference between domestic and non-domestic equids is anesthesia,” said Sanchez. “We use ultra-potent narcotics on zebras, the same ones used on rhinoceroses and elephants, because the animals are so hard to anesthetize.”

During the 90-minute procedure, Brown performed an exploratory laparotomy in order to confirm the colic diagnosis. A twist of the large colon was found that was the source of Dante’s illness. The twist was corrected and there was not any significant damage to the intestines.

“Dr. Brown made the surgery look easy but it was not,” said Sanchez. “Fortunately, she didn’t have to remove any section of the intestines.”

Brown was pleased with the outcome of the procedure and left the determination of a post-treatment regimen to the zoo’s veterinarians who specialize in caring for wild animals.

“Zebras can not even be hooked up to an IV without anesthesia so we left his recovery to the experts,” said Brown.

Following the surgery, Dante was kept at the zoo’s hospital in a padded stall, treated with antibiotics and pain medication, and gradually reintroduced to a normal diet. He was discharged approximately 10 days after the surgery.

“We didn’t have the luxury of checking the incisions in person once he was released from the hospital, but we took pictures with a zoom lens camera and could see that they healed well,” said Sanchez.

It has been two months since Dante was treated for colic and zoo officials report that, as part of the African Savannah Exhibit, he is once again happily greeting the more than two million visitors who flock to the park each year. Along with Gumu, a four-year-old Grevy’s zebra stallion, Dante is part of a conservation effort managed by Species Survival Plans (SSPs), a cooperative breeding and conservation program for selected species in zoos and aquariums in North America. The National Zoo participates in the Grevy’s Zebra SSP not by breeding animals but rather by housing juvenile stallions until they are sexually mature at approximately four to five years of age. They are then sent to accredited organizations in North America that do actively breed this species.

“Dante is a young zebra and very healthy,” said Sanchez. “He handled the surgery really well. The outcome was wonderful and we were grateful that everything went as planned.”

For Brown, working with the zoo’s veterinarians to cure Dante’s colic was a gratifying experience.

“It felt good to be able to help and it was fun to do something different,” said Brown. “I certainly would go again if they needed me.”

Virginia Tech’s Marion duPont Scott Equine Medical Center is a premier full-service equine hospital located in Leesburg, Virginia, that offers advanced specialty care, 24-hour emergency treatment and diagnostic services for all ages and breeds of horses. One of three campuses that comprise the Virginia-Maryland Regional College of Veterinary Medicine, the center and its team of equine specialists are committed to providing exceptional treatment to patients, superior service to clients and cutting-edge research to the equine industry.

Whitford and Aragonas Persevere To Prix St. Georges

Republished by permission of The Chronicle of the Horse. Visit www.chronofhorse.com to subscribe.

An injury almost cost Aragonas his competitive career, but his dedicated owner didn't give up hope.

Laura Whitford just knew she'd found her dream horse the first time she saw him. She was so certain, in fact, that she purchased Aragonas on the spot, the night she tried him.

Whitford, of Shadow Fox Farm in Haymarket, Va., has been showing horses since the age of 11. But it wasn't until that fateful night in March of 2002 that she truly felt that she'd met her ideal competition partner.

"You know how it is when you fall in love? When it's a perfect match? The first time that I saw him, I just knew he was the right one for me. He was my little sports car," said Whitford.

Aragonas, nicknamed Sporty, is an Oldenburg (Argentinus--Saskia) who was bred in Germany. He'd been imported to the United States two years earlier.

"He was so much fun. A friend who was with me said, 'This is the one--this is the Ferrari. This is the sports car that you're looking for,' " said Whitford.

Unfortunately, only two weeks after she brought Sporty home, she noticed that something was wrong. "I'd only had him a short time when we became aware of the injury," said Whitford. "There was no incident that we can trace unless it happened in shipping. You never know with these injuries."

Whitford took Sporty to see Kent Allen, DVM, of Virginia Equine Imaging, in Middleburg, on March 20, who diagnosed the horse with proximal suspensory desmitis of the hind limbs, a common injury in athletic horses that results in a sudden onset of lameness.

When Whitford heard the news, she was understandably shaken. "I was crying. I was really upset," said Whitford. "I've had a lot of horses over the years, but this one was special to me. I was disappointed because I had just gotten him and he was going to be my main competition horse."

According to Allen, proximal suspensory cases of the hind limbs are always significant injuries. Although the cause of this particular injury is unknown, Allen said that these injuries are usually athletic ones incurred when, during a workout, the horse hyper-extends its hind limbs.

"We told Laura that this would be a difficult problem to recover from but that there were both medical and surgical treatments available for it," said Allen. "If a case is a candidate for medical, we usually try the non-invasive procedures first."

The Last Resort
Allen treated Sporty with shockwave therapy and prescribed first resting and then walking the horse. On April 18, Sporty was found to be sound during his exam and seemed to have responded well to the therapy. However, in May the lameness recurred.

"For rehabilitation, we keep the horse at a walk and steadily progress," said Allen. "He was in that process when he became lame again."

Having exhausted the available medical options, Allen referred Whitford to Nat White, DVM, of Virginia Tech's Marion duPont Scott Equine Medical Center in Leesburg, Va., for surgery.

White, a world-renowned equine surgeon and director of the center, conducted a lameness exam on July 2 and diagnosed Sporty as having grade 1.5 lameness. At the time, White was leading a study on the results of a new surgical procedure called proximal suspensory desmoplasty that he had engineered for treating proximal suspensory desmitis.

According to White, the procedure is used for injuries of the dispensary ligament at the attachment to the bone that do not respond to rest. "For some patients, those lesions and ligaments will not heal, so I created this procedure to stimulate the healing process," said White.

Using an ultrasound-guided desmoplasty knife, incisions are made to the suspensory ligament to allow splitting along the entire length of the core lesion. This decompresses the area of injury and stimulates the development of new blood supply and cells to heal the defect. It also appears to help the ligament re-attach to the back of the cannon bone.

"We want to stimulate the core lesion, which constitutes a loss of normal suspensory ligament fibers in the center of the ligament," said White. "We use the surgery to release the pressure in this area and to encourage healing."

White recommended Sporty as a candidate for this innovative technique and advised Whitford that Sporty's chances for recovery were approximately 80 percent. The study later concluded that 85 percent of the participating horses were able to return to full work after undergoing surgery and rehabilitation.

"We had a number of horses that had gone sound after this surgery," said White. "These were horses that had had relapse injuries or had experienced months of lameness and had not responded to shockwave treatment. The chronicity of Sporty's condition left this as a last resort for curing this problem."

Meanwhile, the emotional strain of seeing her beloved horse continue to battle for his health began to take a toll on Whitford. "I was to the point of almost giving up on horses," she said. "As a breeder, I've had my share of issues since mares and foals are also quite fragile, but this one was extremely disappointing."

Whitford was grateful for the emotional support that she received from White during that difficult time. "I remember when I was in the parking lot crying and Dr. White put his hand on my shoulder," said Whitford. "He has an excellent bedside manner and is very compassionate."

Patience Rewarded
On Dec. 18, White performed a successful proximal suspensory desmoplasty on the horse. Sporty was released from the hospital the following day with strict instructions for a controlled rehabilitation that included gradually increasing exercise.

"It requires a month of absolute stall rest after the surgery and then an increasing exercise routine," said White. "First at hand walking, then walking under saddle and then walking and trotting under saddle over four to six months. The level of exercise is determined by the sequential ultrasound examinations of the ligaments after surgery. The rehabilitation is just as important as the surgery itself."

Whitford described the initial stages of the recovery process as tedious. "In the beginning, I was concerned about whether it was going to work or not," said Whitford. "Sporty was really stiff at first from standing so much. It was hard to tell what didn't hurt."

Under the guidance of trainer Jim Koford, she worked patiently to ease Sporty through the beginning stages of rehabilitation. As the signs of Sporty's recovery became more apparent, she knew that the time spent on rehabilitation would be worth it.

"The fitter he got and the more he walked, the better he got," said Whitford.

During the remaining 21 1/2-year rehabilitation period, she worked slowly and carefully to bring Sporty back to top athletic condition. "He tolerated all of his rehab and care pretty well and with good humor," said Whitford. "He is sassy, but at the same time very well-behaved. I can tell you that there are not too many horses that after nine months of stall rest would allow Dr. White to perform an ultrasound of the area behind the hock while seated at a vulnerable angle with machines and vet students standing up close and personal and with absolutely no sedatives."

She decided to be overly cautious and not to rush the horse into competition until he was fully healed.

"I was wondering if I would ever be able to compete him, but by the end of two years, he was so greatly improved that it was amazing," said Whitford.

Another benefit of the rehabilitation was an enhanced relationship between the horse and rider. "It gave us lots of one-on-one time--time to talk about his rehab, our goals together, and how to solve the world's problems," joked Whitford.

Her patience and dedication were rewarded when Sporty competed in his first post-surgery competition, the VADA/NOVA Summer Show in Leesburg, Va., in June 2005. "That was a scary one," said Whitford. "He was a bit shaky but we were glad to be there."

Now, four years after Sporty underwent surgery, the two have moved up to the FEI levels and currently compete at Prix St. Georges. Whitford cautions against pushing a recovering horse beyond its limits, however.

"Continued vigilance to guard against overwork and bad footing is a must! Riders should always check the footing to make sure it's not too deep," said Whitford. "This is very important."

White noted Whitford's perseverance as an essential ingredient in Sporty's recovery. "Laura was persistent, and she did everything that we asked her to do," said White. "That includes the fact that when we told her she needed more time for recovery, she was willing to take the time."

When asked what in particular she loves about Sporty, Whitford notes his loving nature. "He's a great horse because he has so much heart," said Whitford. "He's talented and tries hard. He's a showman. He always seems to know when he has an audience--which sometimes is not good as he's a bit of a show-off--but I also think that that is what makes him a good competition horse."

If she were able to give advice to other owners whose horses suffer potentially devastating injuries, it would be to have faith.

"It takes a lot of rest and rehabilitation work, but you have to be patient," said Whitford. "You have to be committed to going through the process. Don't push the horse too fast after the surgery and don't give up."