Hank the chimpanzee died in January from fluid around his heart, according to the University of Tennessee College of Veterinary Medicine's Department of Pathobiology report.
The necropsy report notes: "It appears based on the gross findings that this animal died due to heart disease with cardiac tamponade."
Tamponade is the medical term for compression of the heart caused by fluid buildup.
The full report is to be faxed to the zoo later today, according to zoo board member and spokeswoman Robin Derryberry.
Zoo Director Dardenelle Long said, "Our staff misses Hank every single day.
"We know he had a great life here at the zoo and the report points to the fact that Hank was simply facing challenges of aging," she said. "We appreciate the time the University of Tennessee took in looking at everything possible in determining the cause of death of our beloved friend."
For complete details, read Tuesday's Times Free Press.