Sydney, Dec 1 (IANS): Veterinary scientists have made a breakthrough in protecting endangered Australian sea lions from an often-fatal infection.

Researchers from the University of Sydney (USYD) and the University of Adelaide estimate hookworms can account for up to 40 per cent of deaths of young sea lions, known as pups, who ingest the worm larvae in their mother's milk soon after birth.

The parasites are among factors which have led to the marine mammal's population plummeting to less than 10,000 around Australia's western and southern coasts, Xinhua news agency reported.

The scientists' findings, published in the International Journal for Parasitology: Parasites and Wildlife and unveiled on Wednesday, show that applying the drug Ivermectin, which is widely used to treat parasites in other species, onto the pup's skin reduces worm infestations by almost 97 per cent.

Project lead Dr. Rachael Gray from USYD Faculty of Science told Xinhua that the team had been thrilled by the success of their trial on about 85 pups at a sea lion colony on Dangerous Reef, off the coast of South Australia.

"We weren't sure how suitable it would be on aquatic animals where it could wash off," Gray said. "But it's highly effective; we only have to treat them once and they don't get reinfected."

She said on a return trip to another Australian sea lion colony last week, where the treatment had been recently undertaken, the researchers were delighted to see how well the pups were doing.

"It's great to see these pups that you've known from birth, looking nice and fat and just really thriving," she said.

"I feel so privileged to work with these beautiful, charismatic animals and the people that care about them."