03/08/2012 03:54 EST | Updated 05/08/2012 05:12 EDT

Calgary Zoo elephant's pregnancy raises herpes concerns

News that an endangered Asian elephant at the Calgary Zoo is pregnant is raising concern about elephant herpes and the health of the calf.

The pregnancy of the elephant named Rani is exciting news for many zoo patrons, but one animal protection group wonders if the zoo should be allowing this particular elephant to breed.

Rani had her first calf, Keemaya, in 2004 and another, Malti, in 2007. The first died shortly after being rejected by its mother at birth.

The second calf was also rejected, but the two elephants bonded a few months later. Malti died about a year later of elephant herpes virus.

Elephant endotheliotropic herpesvirus infects cells lining the body’s blood vessels, which causes hemorrhaging and leads to a vascular collapse that can kill its victims within weeks.

Zoocheck Canada's Julie Woodyer says she was shocked to hear the 21-year-old elephant is pregnant.

"It's completely irresponsible to be breeding into an elephant herd where you know there's a herpes virus," she said.

Researchers making strides

In the past 20 years, the virus has killed about a dozen young elephants in captivity across North America.

But researchers say they're making strides in testing and treating the virus.

Two young elephants were nursed back to health at a zoo in Missouri.

"We're hoping now these animals have established a robust immunity to these viruses, their own immunity, and presumably that's going to help protect them for the rest of their lifetime," said Dr. Paul Ling, an associate professor at Baylor College of Medicine in Houston.

Calgary Zoo officials also say anti-viral medicine has improved — and so has Rani.

"We feel Rani has learned a lot from her previous two births," said zookeeper Colleen Baird, adding the zoo is confident the elephant will be a better mom this time.

Rani part of a species survival breeding program

Rani isn't due until February 2013, but the zoo is already preparing for the birth.

"We are involving a lot of different experts this time," Baird said. "We are reaching out to other facilities as well. We're engaging in a different way than perhaps we have in the past."

Baird says there is a possibility the elephant herpes virus could strike again because it is prevalent in the wild and in zoos. But even Rani herself survived. She was was born at the Calgary Zoo to mother Kamala and father Bandara in 1990.

There are four elephants at the Calgary Zoo — three females and one bull male named Ganesha, otherwise known as Spike, who impregnated Rani all three times.

"This is her third pregnancy and we're always excited," Baird said.

Asian elephants are endangered and Baird says the Calgary Zoo is part of the species survival breeding plan.

The program's mission is to co-operatively manage specific, and typically threatened or endangered, species population within accredited zoos.