Wildlife Rescue Emergency Service vice-president Jo Lyall said she regularly saw the distressing aftermath when people thought they could raise native animals.

“There’s so many factors to caring for these animals and generally people don’t have a clue (about them),” she said.

“It’s not until these animals are crook, lethargic or have passed away that people realise they need experts to step in. That kind of care is so involved.”

Last month a joey was taken in at WRES’ Golden Square shelter.

Ms Lyall said the odour of its feces showed it had been cared for by someone who had fed it dairy milk or baby formula. 

The joey’s health did not improve and it later died.

Ms Lyall said WRES rescue hotline operators often knew something was wrong when callers asked for care tips. 

“We ask them who they are and they might say ‘don’t worry about it’, then they hang up. A few weeks along the track we’ll get a call because someone’s ‘found’ a sick animal.”

One recent rescue involved a woman who had kept a joey at her home.

“The problem was that when joeys are small they need their mother to keep them clean of fecal matter,” she said.

“The woman had been keeping the joey in a towel by the fire. Poo had literally baked onto its skin.”

Ms Lyall said the joey needed an extended soak in water before the fecal matter came loose.The skin beneath had become red and welted.

While it was common for animals who came to the shelter from inexperienced carers to die, there were those who survived.

A possum housed at the service’s Golden Square shelter was currently rehabilitating after being tamed.

“It has no constructive fear of humans whatsoever … I want it to see me as a threat and not come out of its shelter. That way it won’t do it for any strangers once it’s released.”

Ms Lyall said “dehumanising” the possum was a slow and careful process, one that would only finish once she was absolutely sure the possum had developed a healthy fear of humans.