“Thus far in all the cases I’ve seen where the joey has ingested some of the toxin it was with it passing through the mum’s milk as opposed to the joey eating the rat bait directly like the mum did,” Raewyn Jeganathan of the Waratah Wildlife Shelter told the Lilydale Star Mail after a brushtail possum joey survived secondary rodenticide poisoning.
The joey’s mother likely consumed rat bait directly, passing the anticoagulant toxin to her offspring through her milk. Jeganathan nursed the young possum back to health using doses of Vitamin K.
“They get blood pooling on the soles of their feet, it looks bruised, general paleness and lethargy and it had a little bit of frank blood in his faeces,” Jeganathan said.
The joey needed a couple of doses of Vitamin K daily for the first few days, followed by one dose every day for up to twenty-eight days to fully clear the toxin from its system.
Jeganathan said that suburban residents often lack education regarding safe rodent control.
“I pondered over it, and I wonder if the issue is that in suburban areas there’s possibly even less education about rodent control… I think a lot of these people probably just get Rat Sack or whatever it’s called at Woolies and just toss it up into their ceiling space without realising that it could be possums they’re hearing,” she told the Lilydale Star Mail.
Brushtail possums are particularly vulnerable due to their feeding habits. “Brushies in particular are quite greedy, I always jokingly call them garbage guts, they’ll give anything a try, anything has the potential to be a good snack,” Jeganathan said.
A 2024 study published in the journal Science of The Total Environment found that 91 per cent of brushtail possums and 40 per cent of ringtail possums observed had rodenticide in their systems. Jeganathan called these figures disconcerting, noting that extended exposure is required to develop such tolerance.
In March, the Australian Pesticides and Veterinary Medicines Authority (APVMA) recommended restrictions on products containing second-generation anticoagulant rodenticides (SGARs) due to lethal poisoning risks for native wildlife including owls, quolls, goannas, and eagles. Pending further decisions, this restriction will lift in March next year.
Safer poisons and bait stations are more expensive upfront, but require smaller quantities during targeted programs.
“I would love it if people didn’t use bait at all, but I think I’m realistic enough, especially living in a semi-rural area where there’s a lot of horsey properties that if you just banned it all together, that you would then end up with a plague of rats and mice,” she said.
