With the world’s largest medical center located right next door, it is no wonder that the Houston Zoo has paired up with some of the best human physicians and researchers to collaborate on important issues that affect our ecosystem.
As experts in their respective fields, Jose Banchs, M.D., FACC, FASE, director of echocardiography at The University of Texas M.D. Anderson Cancer Center, and Paul Ling, Ph.D., a longtime herpes virus researcher at Baylor College of Medicine, extend their knowledge of human health issues to the vets at Houston Zoo.
Ling and Banchs work on separate projects with the zoo. Banchs helps care for the orangutans and chimps as part of the Great Ape Heart Project and Ling studies blood and trunk wash samples taken from the Asian elephants to monitor levels of elephant endotheliotropic herpes virus (EEHV), a virus that is the leading cause of death in juvenile Asian elephants in North America, and may be contributing to their decline in the wild.
“We are very grateful for everything the medical center has done,” said Houston Zoo Veterinarian Lauren Howard, DVM. “Being right across the street certainly helps facilitate our relationships with the institutions and helps us to provide great patient care.”
Banchs and his team monitor the apes’ cardiac health through the use of regular heart ultrasounds, performed while the animals are under anesthesia. They take heart measurements to evaluate cardiac function, and then work together with the zoo veterinarians to develop a treatment plan.
“To see that they have the exact same structure, an exact same fiber orientation in the heart to human beings, it’s just very enlightening,” said Banchs.
Heart disease an important cause of sickness and death in apes in captivity, and it is important for zoos to monitor cardiac health in their ape populations. Little is known about the incidence of heart disease in apes in the wild.
It’s not uncommon for zoos to seek out input from human cardiologists when treating apes. Apes are closer in heart anatomy to humans than they are to any other animal. In fact, they are almost identical. For this reason, human cardiologists, rather than veterinary cardiologist, are more appropriate to offer assistance.
“Our preventative medicine protocols are always evolving, so when we wanted to participate in the Great Ape Heart Project more and do better cardiac exams on our great apes (orangutans at the time) we contacted several zoos to ask what they did,” said Maryanne Tocidlowski, DVM, associate veterinarian at the Houston Zoo. “Many of them had human cardiologists as consultants because of their expertise with the heart exam and cardiac equipment. Banchs and his technician Liza Sanchez came over and apparently became enthralled with our animals. They have been coming over to do our cardiac exams ever since. We are ever grateful to them for their assistance.”
In 2009, when Banchs was first brought in to work with the zoo, he helped confirm that a Bornean orangutan, Doc, was suffering from severe heart disease. Taking advice from Banchs, the veterinarians put Doc on human heart medication, but unfortunately treatment was initiated too late to turn his illness around. Doc was euthanized in August 2001, due to severe cardiomyopathy—an inability of the heart muscle to contract effectively.
Before Doc was euthanized, Banchs and his team were present to perform one final cardiac exam, to learn as much as they could about Doc’s condition. Banchs said his last moments with Doc really moved him.
“It was very sad to see him suffer so much,” said Banchs. “You see that familiarity between the keepers and the animals and at that moment when a human who has been taking care of this animal for more than a decade or two realizes they are losing the animal who is like a relative to them, it was very moving.”
The project continued after Doc’s death and a few years later it was discovered that Rudi, another male orangutan was suffering from decreased cardiac function. This time, though Rudi was not showing any clinical symptoms of cardiac illness, the team decided to take a more aggressive approach.
Rudi was put on human medications for heart failure, a beta-blocker and ace inhibitor, and the keeper staff gives him his medications twice daily. Those medications, combined with an improved diet and enrichment-motivated exercise, have helped Rudi lose over 100 pounds.
“Clinically, Rudi acts perfectly fine and he probably doesn’t realize his heart is not normal,” said Howard. “Had we not done the routine heart exams that are recommend by the Great Ape Heart Project, we would not have noted his decreased cardiac function so early on, and he might be clinically ill by now. Because of the medication and assistance from Banchs, Rudi continues to lead a normal healthy life.”
Meanwhile, Ling heads up the research team that closely monitors the Asian elephants at the zoo. The project, a collaboration between Baylor, the Houston Zoo and Johns Hopkins University, is helping scientists and elephant caretakers all over the world learn more about the virus that is causing sudden deaths in the young elephants.
EEHV is a recently discovered virus that scientists have very limited information on. The virus can affect both Asian and African elephants, with the majority of fatalities occurring in young Asian elephants.
In 2008, a two-year-old elephant, Mac, passed away at the Houston Zoo due to EEHV infection. His death came as a shock to the staff.
The virus can cause illness very acutely, and by the time Mac started to show symptoms, it was too late for treatment to help him. He died less than 24 hours after displaying his first signs of illness.
“Baylor approached us when Mac died in 2008,” said Howard. “Alan Herron, one of the veterinarians at Baylor, reached out to us to express sympathy, and he asked if there was anything that they could do. That’s when we said ‘Yes, give us a virologist.’ Alan initiated the first meeting between Paul’s group and us.”
“All it took for me was one visit to the zoo,” said Ling. “The elephants are very charismatic animals and I thought how could I not want to save baby elephants? So I decided then that I would work on it and if there was a will there was going to be a way.”
Currently, the zoo has four juvenile elephants that are considered at high risk. Every week Ling tests samples from the elephants to watch for the presence of EEHV.
“The investigative abilities Dr. Ling and his research team have provided have really opened doors in helping us understand and manage this disease,” said Howard. “Not only for our elephants in the zoo but throughout the world. His work has had very far reaching effects.”
Initially, the collaborators worked under very tight finances. Luckily, with the help of private donors and the Houston Zoo, the team was able to establish the research program. Eventually the Houston Zoo received a $500,000 grant from the Institute for Museum and Library Services, a highly competitive grant program.
“The medical center is used to million dollar grants but in the zoo world getting half a million dollars is pretty spectacular,” said Howard. “Zoo grants are normally between $10,000 and $50,000, so it’s a really big deal.”
With the help of this grant, and support from the Houston Zoo, the research program has divided its goals into three phases: diagnostics, treatment and creating a vaccine. The team is well underway on their first goal and has created several successful testing methods.
Now, their focus is on the second phase, looking at better understanding the elephant immune system and how that will affect treatment options.
“We’re currently working on developing tests to look at elephant antibody responses and cellular immune responses to understand how the elephants respond and develop immunity to the elephant herpes virus,” said Ling. “Both of those are going to be important for helping elephants clear the initial infection and then maintain the lifelong immunity to the virus.”
Together, the collaborators host international conferences every other year to share their research with other scientists and elephant experts. They believe this issue is critical in maintaining the species and hope to soon develop an effective treatment plan and vaccine to help save elephants all over the world.
“Elephants are certainly a unique species,” said Ling. “It’s a flagship animal at almost any zoo that you go to and we know it’s killing elephants in the wild. I think solving the EEHV problem could be a critical piece that we’re going to have to do. It might sound a little melodramatic, but we’re going to have to solve this problem, potentially if we want to save the species.”
As Ling and his collaborators continue to search for answers, it is clear that the support of the Texas Medical Center physicians and researchers is incredibly important to the Houston Zoo.
“With all this talk of emerging diseases and zoonotic diseases, I think there is actually a unique opportunity for the zoo and the medical center and all the resources here to come together and look at some of these problems in a unique way,” said Ling. “What other place do you know of that has this number of high powered research institutions working on human health that are located right next to a very high profile and well respected zoo? I can’t think of any place.”