Crocodile farmers spend years raising reptiles from eggs to adulthood, but the West Nile Virus (WNV) can undo that time and investment. 

Researchers have developed a vaccine for the virus that causes tiny white spots on crocodile skins and threatens to wipe millions from the $40 million industry.

"Saltwater crocodiles produce the best crocodilian skin in the world," said Charlie Manolis, a chief scientist with Wildlife Management International and crocodile farming industry veteran.

"Those skins are going into the top line of products at Hermes and Louis Vuitton."

But, if the animal has been infected with the mosquito-borne WNV, it's a different story.

"If it [the virus] is there, or has been there, when that skin is tanned, then it'll leave little holes in the skin," Mr Manolis said.

"It's not like we're throwing them away, but they go into a different market where the value is a lot, lot less."

While WNV damages crocodile skin, it does not otherwise harm their health.

University of Queensland researcher Jody Hobson-Peters has led a team to develop a vaccine for the Australian variant of WNV, known as Kunjin virus.

The researchers used a benign Australian virus called Binjari to develop the vaccine, which was administered in two shots to hatchlings aged about four months.

Dr Hobson-Peters said it was the first time researchers had tested this type of vaccine in cold-blooded animals.

"We were very surprised to see how effective it was," she said.

Dr Hobson-Peters said testing of the animals' immune responses in the months afterward produced promising results but there was still more to do.

"We've just secured some funding from the Australian Research Council to progress this work further so that we can actually look at the longevity of the immune response developed against the vaccine," she said.

Dr Hobson-Peters also hoped the vaccine would be able to be used on other crocodile and alligator populations overseas.

"Because of the similarities between the Australian West Nile Virus strain and those overseas, we do believe that our vaccine will likely be as protective against other strains of West Nile Virus," she said.

She said this could also have benefits for human health. Crocodiles can transmit WNV back to mosquitoes, which can in turn transmit the virus to humans or horses and cause fevers and sometimes encephalitis.

Mr Manolis said the domestic crocodile farming industry would likely be receptive to a vaccine.

"I wouldn't say that it's going to deal with everything that you have to deal with any sort of farming with an animal with 68 sharp teeth … but it's certainly going to be a good step in the right direction," he said.