Dog owners warned to be wary of deadly berries

Dog owners are being warned to watch out for a toxic native tree responsible for killing animals this summer.

In Auckland, at least two dogs have died in the past week after eating the berries from karaka trees.

The Karaka tree's distinctive berries are extremely common and extremely deadly.

Aprilanne Bonar had to watch her dog, Malo die after he ate the berries, and she's now on a mission to save other pets from a similar fate.

The native tree grows in the North Island and the upper half of the South Island, and their berries are a major food source for wood pigeons.

But the fresh kernels inside contain the alkaloid karakin, which can be fatal to other animals - including humans.

Vet Mark Robson this week treated three dogs that had eaten the berries.

"It's terribly traumatic because they're out for a walk with their dog, nobody's aware berries are there dogs can eat, [and] just six or 12 hours later it's dead. It's devastating," he said.

He says he's not sure why, but this year the berries are highly toxic and cases of poisoning far more frequent.

"It's going to be in the dozens, and because it's so highly fatal it's important people understand the risk," he explained.

Dog owners are urged to familiarise themselves with the trees and keep their animals well away from the berries.

They've also been warned to go straight to the vet if the dog eats even one of them.