It might not be the kind of call she receives every day, but Dr. Jennifer Brown didn’t hesitate to respond.
A faculty member at Virginia Tech’s Marion duPont Scott Equine Medical Center in Leesburg, Brown lent assistance to the Smithsonian National Zoological Park when one of its two zebras became ill with a life-threatening case of colic.
On Aug. 27, Brown, clinical assistant professor in emergency care and equine surgery at the Marion duPont Scott Equine Medical Center, performed an operation on the 2-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 Aug. 26.
“Any time that one of these animals is sick, it is pretty challenging because, as prey animals, they tend to hide pain,” said 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.”
The veterinarians anesthetized the zebra with a dart and performed a diagnostic examination for colic.
“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 intestinal blockages, 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 Suzan Murray, chief veterinarian at the 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.”
Colic is one of the EMC’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 EMC.
“We treat donkeys and mules and the occasional exotic species.”
Like a horse, a zebra’s digestive system consists of intestines that stretch from 11 to 12 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, Va., to the zoo in Washington to conduct the surgery. National Zoo staff attending Dante’s procedure included Murray, chief veterinarian; Sanchez, associate veterinarian; 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 EMC’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 to be 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 cannot 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.
Since Dante was treated for colic, zoo officials report that, as part of the African Savannah Exhibit, he is once again happily greeting the more than 2 million visitors who flock to the park each year.
Along with Gumu, a 4-year-old Grevy’s zebra stallion, Dante is part of a conservation effort managed by Species Survival Plans, 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 4 to 5 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.”
Grevy’s Zebra By The Numbers
- 9 feet long
- 990 pounds
- 30 percent of their diet may be leaves, in addition to the tough grasses they eat
- 13-month gestation period
- 3 years: how long a foal in the wild may stay with its mother
- 20 years: how long they may live in captivity (shorter in the wild)
- 6,000: maximum total wild population
- 17 hands: size the zebra may reach, the largest wild member of the horse family
- 3: different species of zebra—Grevy’s (named after a French president who received the first specimen known to the scientific world), the common zebra and the mountain zebra. Grevy’s is the largest, with huge ears and narrow stripes.