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By Dr Michelle Dalli, North Richmond Vet Hospital & Tom Covell, Hooked on Nature
With winter comes that all-too-familiar scurrying sound in the roof or shed as rats and mice look for warmth and shelter. We know how frustrating it is. We’ve personally felt the fury when rats chewed through thousands of dollars’ worth of our camping gear. We saw red. As much as we wanted to get rid of them immediately, we also knew through both the vet clinic and our work in ecological education how deadly rat poison can be to pets and wildlife.
At North Richmond Vet Hospital, we regularly treat cats and dogs that have been poisoned by rodenticides and heartbreakingly, not all survive. Some require intensive care, including blood and plasma transfusions. Even with everything we can throw at them, some don’t pull through. It’s absolutely gut-wrenching for the families involved, and it’s a horrible way for a pet to die.
But the damage doesn’t stop at pets. We’ve also seen native wildlife suffer the same fate; Powerful Owls, Boobook Owls, Masked Owls, Tawny Frogmouths, Kookaburras, hawks, and eagles. These magnificent predators often never even come near a bait station, yet they’re still dying because they eat poisoned rodents. That’s what we call secondary poisoning when an animal eats a rat or mouse that has already consumed poison. The worst culprits are second-generation anticoagulant rodenticides (SGARs) like Brodifacoum, Bromadiolone, Difenacoum, and Difethialone. These are incredibly potent, lethal after a single feed, and they stick around in rodent tissues for weeks. They can wreak havoc on entire food chains. Worse still, SGARs bioaccumulate, they build up in the bodies of predators and scavengers, and they can even reach humans. It’s a serious risk. First-generation poisons (FGARs) like Warfarin and Coumatetralyl are less persistent and require multiple feedings to be lethal. They’re still dangerous but pose a lower risk to wildlife and pets.
Honestly there are better ways. We now focus on non-toxic alternatives snap traps, rodent-proofing buildings, and removing food sources. We also work with nature: habitat gardens, owl nest boxes, and even welcoming Diamond Pythons (who are completely harmless to us) have helped keep rodent numbers down in a safe and sustainable way. What harms a rat today could kill a pet or an owl tomorrow. We all need to think carefully about how we manage pests for the sake of our families, our animals, and our native wildlife. If you think your pet may have eaten bait, get them to the vet right away early treatment can save lives. To learn more, visit: www.actforbirds.org/ratpoison
