EDMONTON - This is showdown week in the battle between zoo officials, animal rights groups and a retired game-show host over whether Lucy the elephant should be moved to the U.S. where she could be with other elephants.

Bob Barker, a well-known animal activist and the former host of "The Price Is Right," will travel to Edmonton on Thursday to convince people that Lucy needs to be relocated because having a lone elephant at any zoo amounts to torture for the highly social animals.

But Edmonton's Valley Zoo delivered a pre-emptive public relations strike Monday by releasing an independent evaluation which concludes that moving the 34-year-old elephant could end up killing her.

Dr. James Oosterhuis, a California-based veterinary consultant, said Lucy's nasal passages are severely restricted, making it difficult to breathe through her trunk.

She has adapted by learning to breathe through her mouth, but in stressful situations such as travelling, Lucy finds it difficult to get enough air, he said.

"Her current respiratory problems preclude any thought of moving her and in fact, it would be life threatening," Oosterhuis said in a letter to the Valley Zoo. "It is my opinion that it would be unethical for any veterinarian to recommend moving her."

Barker and the animal rights group Zoocheck have been campaigning to have Lucy moved to a sanctuary in the United States.

In an interview from his office in California on Monday, Barker said that even after reading the independent review, he's still not convinced that Lucy should remain in Edmonton.

"We don't have any intention of trying to move Lucy until she's healthy enough to travel," said Barker. "But the moment her health is restored, it's time to get Lucy out of there."

William Shatner, of "Star Trek" fame, has also added his voice to the growing movement to have Lucy relocated. Shatner has written to Edmonton Mayor Stephen Mandel in hopes of persuading him that Lucy needs to be moved to a facility that has other elephants.

"These extraordinary animals are everyone's responsibility... she's old, feeble and many of us know how that feels," wrote Shatner, adding that Edmonton's long and frigid winters mean that Lucy spends the majority of her time indoors.

Last May, a number of Canadian authors, including Barbara Gowdy, Elizabeth Abbott, Margaret Atwood and Michael Ondaatje, sent a letter to the Mandel with a similar pitch.

Zoocheck has launched a website and is running ads in Edmonton to win public support.

"Your tax dollars pay for her suffering," says one of the Zoocheck ads. "Isolation and bitter cold winter on the way. Hasn't she endured enough?" reads another.

Elephant behaviour expert Dr. Joyce Poole wrote the city a letter in July that said "after 32 years of captive misery, Lucy deserves to be given what is in her best interests."

But zoo officials in Edmonton are standing firm in their resolve to allow Lucy to live out the rest of her natural life at her current home, which they say could be another 30 or 40 years.

"To transport an elephant of this size is not an easy thing to do and would take a number of days," Dr. Milton Ness, the Valley Zoo's veterinarian, told a news conference Monday.

"To have Lucy at her brink of respiratory capacity (for several days) is paramount to signing her death certificate."

The zoo has moved an elephant before. Lucy's companion Samantha, an African elephant, lived at the Edmonton zoo until September 2007 when she was shipped to a breeding program in Asheboro, N.C., leaving Lucy on her own.

Oosterhuis spent hours examining Lucy and at one point snaked a scope down her trunk to find out why she doesn't breathe normally. In an interview Monday from his office in San Diego, he said further tests are needed to determine how to treat Lucy.

"I'm here to help her with her medical problems," said Oosterhuis. "If we can get her through her medical problems, then other decisions will have to be made by other people and that doesn't involve me."

Lucy's breathing problems may eventually be cured in a year or so, but Oosterhuis appeared reluctant to wade into the debate over whether the elephant should be relocated.

"Anything is possible," he said. "You couldn't make a decision until she's completely free of whatever her problem is right now with her nose."

Zoo manager Linda Cochrane said they have invited Barker to meet Lucy when he's in Edmonton this week. But she said the zoo is not interested in getting involved in a battle of experts over Lucy's future.

"We will not allow any further external veterinarians to examine Lucy," said Cochrane. "We're not about to put Lucy through any more stressful procedures to simply tell us what we already know."

Although zoo regulations say elephants should not be kept in captivity in Alberta without the presence of other elephants, the Valley Zoo has been given an exemption because of Lucy's ongoing health issues.