HOUSTON -- The playful, 2-year-old Asian elephant named Mac at the Houston Zoo has died, and the reason for his death has prompted critics to want elephant breeding to stop, KPRC Local 2 reported Tuesday.

Mac died Sunday night after showing signs of elephant herpesvirus.

"This is a problem that faces elephants worldwide, both in captivity and in the wild," Director of Veterinary Services, Dr. Joe Flanagan said Monday. "We're in a unique opportunity to learn more about this and how we can prevent it in the future."

The group In Defense of Animals and People for the Ethical Treatment of Animals said the zoo should stop elephant breeding. They want the Association of Zoos and Aquariums to take away the zoo's accreditation if it continues.

"It's just wrong for the Houston Zoo to expose more young elephants to this awful disease and to cause mother elephants the anguish of watching their babies die this terrible, terrible death," group spokeswoman Catherine Doyle said.

"It's no surprise that IDA is using this sad event to advance their goal of getting all elephants out of zoos," Zoo Director Rick Barongi said. "While we have no guarantees as to the fate of future elephant calves, we do know that stopping breeding in zoos will severely impede the progress that is being made in studying this disease and finding a cure."

Mac's body was sent to Texas A & M University for an animal autopsy.