Source: Whanganui Chronicle (Extract)
Posted: February 2, 2024

Animal owners should be on the lookout for highly toxic karaka berries, as the tree’s fruiting season intensifies between January and April, the New Zealand Veterinary Association Te Pae Kīrehe (NZVA) is urging.

While signs of karaka toxicity have been recorded in humans, sheep, cattle, chickens, and other species, dogs are especially sensitive to the toxin in the orange berry, as they contain the alkaloid karakin. Consumption of the berries by dogs can lead to respiratory failure, impaired neurological function and even death.

NZVA president Kate Hill said early treatment is best, so if you think your pet has ingested karaka berries, call your vet clinic immediately.

“We are already seeing trees absolutely laden with fruit in some parts of the country,” she said. “While karaka berries are an important food source for the kererū, they are particularly dangerous to dogs at this time of year as the berries ripen and fall from the trees.”

Signs of karaka berry toxicity in dogs can be delayed up to 48 hours after ingestion. Signs to be aware of in dogs include:

  • vomiting, diarrhoea, reduced appetite and abdominal pain
  • paralysis of hind limbs
  • loss of balance
  • convulsions
  • reduction in the dog’s breathing rate and eventual paralysis of muscles used for breathing

Preventing any ingestion of the karaka berry is better than treatment. Dr Hill advises pet owners to be aware of where karaka trees are located; keep dogs on leads if walking in an area where karaka trees are present; know the signs of karaka berry toxicity; and if there is concern an animal has ingested the berries, seek emergency veterinary treatment. Even if ingestion has occurred and there are no clinical signs within one to four hours, dogs should be taken to a vet clinic and made to vomit.

The NZVA encourages the use of signage in appropriate areas advising the general public about the potential risks of karaka berries between January and April.

Karaka berries

The amount of karakin in the fruit varies depending on the plant maturity, soil conditions, climate and season. The kernel contains the greatest concentration and may remain toxic in the soil, leading to toxicity outside the fruiting window.

Toxicity has been recorded multiple times with the ingestion of a single berry in various sizes of dogs. Karaka are also a taonga for mana whenua. They are a beautiful native tree and an important part of our history.

They have been used as a food source for hundreds of years when prepared correctly to remove toxins. Midweek was told local Māori would mash and soak the berries for several weeks to make them safe to eat. It is thought they would come ashore at the bottom of Bastia Hill, where the karaka still survives.