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Circulating biomarkers of fibrosis in captive gorillas: a pilot study

Zoo Atlanta
Atlanta, Georgia
DOI: 10.18258/8105
Grant: ZoosGrant: Zoos
Raised of $3,000 Goal
Funded on 12/15/16
Successfully Funded
  • $3,566
  • 118%
  • Funded
    on 12/15/16

About This Project

Heart disease is the leading cause of death for gorillas in captivity. The ultimate goal of this project is to reduce mortality and improve the health and welfare of these endangered primates.

We’ve identified blood tests for biomarkers that are good indicators of cardiac disease in humans. We need to determine if these tests will work for gorilla blood samples. If valid, these simple, inexpensive tests will be invaluable to zoos looking to monitor the health status of their gorillas.

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What is the context of this research?

Improvements in husbandry, medical care, and nutrition have increased the lifespan of captive gorillas. For this reason, age-related diseases including cardiovascular disease are becoming more prevalent. Despite being the leading cause of death, heart disease in gorillas is poorly understood. Diagnosis is currently limited to echocardiography and ECGs which are not available at all zoos, and may not be able to accurately detect the early stages of heart disease, when treatment would be most effective. Development of blood-based tests for diagnosing heart disease is therefore invaluable to zoo veterinarians. This study is part of a larger effort to understand heart disease in great apes.

What is the significance of this project?

Heart disease is a leading cause of death in all 4 species of great apes. Echocardiography and ECGs require advanced training, and are not available at most zoos. Further, these tests are expensive, increase the amount of time an animal must remain under anesthesia, and may fail to identify animals with early heart disease. Therefore, a simple, quick, inexpensive test that makes an early diagnosis would be invaluable to zoo veterinarians. Blood-based tests that identify biomarkers for heart disease exist in human medicine, and may be applicable to gorillas. Further, the information obtained in this study will help change current recommendations for the diagnosis and management of heart disease in gorillas.

What are the goals of the project?

The primary goal of this study will be to evaluate the efficacy of the 5 proposed biomarkers at distinguishing healthy animals from animals with heart disease. We plan to compare concentrations of the blood-based biomarkers between healthy animals, and animals with known heart disease based on echocardiography and ECGs. With the results, we will be able to make recommendations to zoo veterinarians and researchers on which test, if any, are best at predicting heart disease in gorillas. A bigger objective under which this study falls is to better understand heart disease in gorillas so that we can decrease morbidity and mortality of this species.


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In order to determine the validity of these tests, we will need to run several samples from clinically healthy gorillas as well as gorillas with known heart disease. For the entire project, we aim to run 60 samples for each test; 30 samples from diseased animals, and 30 samples from healthy controls. The samples will need to be frozen for shipment and sent to the analyzing lab using FedEx.

We have set our donation goal low, so that we can initiate a pilot analysis of this project. If we win this competition, we will be able to match the remaining funds with our $1000 prize and existing donation funds from the Great Ape Heart Project.

**We've identified 3 additional biomarkers that we'd like to analyze depending on the availability of funding. These were determined following discussions with one of our co-investigators who runs the cardiac biomarker lab.

Endorsed by

I have been affiliated with the Great Ape Heart Project since 2011 as a cardiac ultrasound advisor. The GAHP is instrumental in assisting zoos in identifying and treating heart disease in great apes. So much of what we do in human medicine can often be applied to these highly endangered apes. Being able to validate blood tests for gorillas that can detect heart disease will be an invaluable resource to the zoo community.
The assembled group is in a good position to acquire and analyze samples to evaluate their association with cardiac disease in gorillas. Heart disease in captive gorillas is a critically important problem to solve, and this study may give some insight into the pathogenesis and pathophysiology of fibrosis as a contributing factor to this syndrome.
Cardiovascular disease is a big problem in the great apes and this project has the potential to make a big difference.

Meet the Team

Trevor Gerlach
Trevor Gerlach
Cardiology Resident


University of Georgia College of Veterinary Medicine
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Hayley Weston Murphy
Hayley Weston Murphy
VP of Animal Divisions, Zoo Atlanta
Marietta Danforth
Marietta Danforth
Project and Database Manager


Great Ape Heart Project at Zoo Atlanta
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Gregg Rapoport
Gregg Rapoport
Clinical Assistant Professor of Cardiology


University of Georgia College of Veterinary Medicine
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Team Bio

The Great Ape Heart Project (GAHP) is a group of dedicated and coordinated subject matter experts that provide a network of clinical, pathologic, and research strategies to aid in the understanding and treating of cardiac disease in all the ape species, with the ultimate goal of reducing mortality and improving the health and welfare of captive great apes.

Trevor Gerlach

Dr. Gerlach graduated from the University of Florida's College of Veterinary Medicine (UF CVM) in 2010. Upon graduation, Trevor attended the University of Pennsylvania's Veterinary Teaching Hospital as a rotating intern prior to completing an aquatic animal fellowship with UF CVM. He then became the Associate Veterinarian at Tampa's Lowry Park Zoo before transitioning into his current role as a cardiology resident at the University of Georgia. Through his affiliations and his combined interests in zoo medicine and cardiology, he has completed and published several studies pertaining to cardiovascular disease in non-domestic species. His hobbies include soccer, rafting, and hiking.

Hayley Weston Murphy

Dr. Murphy graduated from the New York State College of Veterinary Medicine at Cornell University in 1992. Upon graduation, Hayley started working part-time at several zoos in the Boston area while working as an equine and small animal veterinarian. She transitioned to zoos full-time in 1995 with a zoo medicine internship at Zoo New England in Boston, MA. Eventually Hayley became the Director of Veterinary Services at Zoo New England and stayed there for 13 years before coming to Zoo Atlanta, where she is presently the Vice President of Animal Divisions. Hayley is also one of the veterinary advisors for the Gorilla Species Survival Plan for the Association of Zoos and Aquariums and is the founder and director of the Great Ape Heart Project, an internationally recognized collaborative project dedicated to diagnosing, treating and preventing cardiac disease in great apes. In her spare time, she is the mother of two teenagers and married to a small animal veterinarian.

Marietta Danforth

Dr. Marietta Danforth graduated from Emory University with a B.S. in Anthropology and received her Ph.D. in Evolutionary Psychology from the University of St. Andrews.

As the Project and Database Manager, Marietta is responsible for the day-to-day operation of the Great Ape Heart Project, including managing the cardiac exam review process, monitoring database submissions, and creating protocols and training support materials for use in the management of captive great apes. She initiates collaborative projects between zoos with the overall goal of building the capacity of professional and support staff at various zoos, sanctuaries, National Primate Centers and hospitals involved in the care of great apes.

In 2015, Marietta finalized the design of the GAHP’s International Cardiac Database, which includes over 300 apes from over 70 institutions world-wide. Her current research is focused on establishing echocardiographic parameters for orangutans, developing blood pressure reference ranges for great apes, and investigating potential genetic markers for cardiovascular-disease in gorillas and bonobos.

Gregg Rapoport

Dr. Rapoport graduated from the University of Wisconsin School of Veterinary Medicine in 1999. He completed a one-year rotating internship in small animal medicine and surgery at the Animal Medical Center in New York City. He then returned to Wisconsin to perform a cardiology residency, which he completed in 2003. He worked in private practice in Michigan for one year followed by four years at the Angell Animal Medical Center in Boston, Massachusetts. In 2009 he took a faculty position at the University of Georgia College of Veterinary Medicine. There he is involved in the Great Ape Heart Project based at Zoo Atlanta, as well as other clinical research projects in the area of small animal cardiology.

Additional Information

This will be a prospective case-controlled study. Captive adult gorillas of both sexes, with known heart disease and that are otherwise healthy, will be in included in the study. In addition, clinically healthy captive gorillas, age-matched to animals with known cardiac disease, will be included. Animals will be anesthetized for other procedures including routine health assessments and pre-shipment examinations at various locations/facilities throughout the United States. Animals will be deemed healthy based on the findings of physical examination, complete blood count (CBC), serum biochemistry (Chem), and urinalysis (UA). Animals with evidence of renal disease (defined as azotemia on bloodwork collected at the time of biomarker analysis, or isosthenuria) will be excluded. Transthoracic echocardiography will be used to determine cardiac disease status. All echocardiograms will be reviewed by a single veterinary cardiologist (GSR).

Sample collection:

Venous blood will be collected from anesthetized animals and submitted overnight to a commercial lab for analysis of the aforementioned biomarkers (submission details will depend on the biomarker and accepting lab). Concurrently, a CBC, Chem and UA (via cystocentesis) will be performed on each animal at the time of biomarker testing. Depending on sample size and the requirements of the biomarker assays, we may opt to submit frozen samples for analysis.

Echocardiograms will be performed at the time of sample collection. Based on review by one investigator (GSR) animals will be segregated into two populations: healthy animals and those with evidence of cardiac disease (defined as increased chamber size or decreased systolic indexes based on previously published echocardiographic normal values).


Results from all five tests in each of the study populations (healthy animals and animals with known cardiac disease) will be compared using appropriate statistical analyses. If the biomarker tests cross react with gorilla blood and statistically significant trends are found for animals with cardiac disease, we may collect more samples to evaluate trends based on the severity of heart disease, and the age and sex of the animals tested.

Distribution of information:

The information obtained in this study will be presented at international conferences and submitted for publication in a prominent veterinary journal.

Project Backers

  • 91Backers
  • 118%Funded
  • $3,566Total Donations
  • $39.19Average Donation
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