Malti was born at the Calgary Zoo in August 2007. (Submitted by Irene Bain)

The future of the elephant breeding program at the Calgary Zoo is uncertain after a calf died from a virus that attacked her blood cells.

Zoo officials confirmed Monday that Malti, a 14-month-old Asian elephant, died from heart failure and shock over the weekend.

The pachyderm contracted elephant herpesvirus last week, which causes internal bleeding that can overwhelm the heart within a few days. Despite being treated with anti-viral medication as soon as symptoms appeared, Malti died on Saturday.

Malti was born to Maharani, who had rejected a calf that later died four years ago, as part of the zoo's breeding program.

Zoo veterinarian Dr. Sandie Black said Friday she doesn't know what the future holds for the program: "We have no plans either way at the moment, and it will be done in consultation with elephant management groups, with the American Zoo Association, with our own community here."

Black said semen doesn't seem to carry the virus, so Spike, the male elephant, will continue to donate for artificial insemination at other zoos.

Visitors leaving cards, flowers

Elephant keeper Les O'Brien said the female elephants held their trunks over Malti's body on Saturday as a way of saying goodbye, and then Maharani nudged the calf's foot.

Visitors have been leaving cards, drawings and flowers at the elephant enclosure. (CBC)

"Heartbreaking to watch, absolutely heartbreaking. However, I really think it helped with closure for them," he said on Monday.

Visitors have been leaving cards, drawings and flowers at the Elephant Crossing enclosure.

"My whole family will miss Mallti. I love Mallti," read one handwritten card that was taped to the enclosure's glass door, and signed by Georgia, age six.

Elephant herpesvirus has been blamed for the deaths of nearly a dozen young elephants in North American zoos over the past 20 years.

Only four elephants have survived elephant herpesvirus with early treatment.

The four adult pachyderms at the Calgary Zoo are being tested to see if they carry the disease, but adults have more resistance and can carry it without being noticeably ill.

Zoocheck condemns breeding

Julie Woodyer of the animal welfare group Zoocheck says the Calgary Zoo's breeding program should be stopped.

"First off, let me just say breeding programs don't work," she said. "The animals don't live long enough. Elephants generally are dying in captivity at about half of their age if they make it out of infancy."

Woodyer says too many animals have died at the Calgary Zoo and she wants a public inquiry.

In recent years, four gorillas have passed away, and a hippo died a year ago after being transferred to the zoo. Forty-one stingrays in a touch tank died in May but tests could not determine the cause.