An unseasonably warm winter has seen a large increase in the number of rats around the Auckland region, leaving family pets the victims of rat poison and essentially dying.
"This has been by far the worst period of poisonings we've ever had with rat bait," vet Mark Robson told 1 NEWS.
"We're not saving all of them because we're getting some of them too late to be able to help them.
"You can't do any first aid at home - you need to get them to a vet as soon as you can."
There are symptoms pet owners can watch out for at home, such as bleeding, breathing problems and severe dehydration.
However, pest control experts advise that a professional should be called to install any rat poison, as rat bait needs to be contained.
Pest control expert Owen Stobbart says it is crucial that non-target animals are unable to access bait or snap traps.