They call Donna Stepan the Wombat Whisperer. At her unique animal sanctuary in Australia, she works around the clock to save injured and orphaned wombats. She has a dire warning about her much-loved wombats: "They'll be on the critically endangered list within 20 years. No doubt in my mind." Donna wants the world to know about the fatal and contagious parasitic disease plaguing Australia's wombats - sarcoptic mange. "In the last decade, it has escalated every single year. The amount of areas with manged wombats just continually increases," she says. In the southern state of Tasmania, mange has wiped out 94 percent of the wombat population in one national park. "We've seen them disappear in their hundreds - just in this area," says Bea Mayne, a volunteer who helps treat diseased wombats with Cydectine, a chemical used to treat sheep lice. "If we see one that's died - and we often do that - it's just heartbreaking." While the government and scientists insist that the overall wombat population is stable, wildlife campaigners are convinced it poses a catastrophic risk to Australia's loved marsupial. At her sanctuary, "Sleepy Burrows", in the state of New South Wales, Donna is working on a new way to treat wombats with mange - by giving them a pill and building "burrow hospitals". 101 East investigates the fight to save one of Australia's most loved native animals.