Danger signs go up after dog dies

Stephanie Winsley exercises her pets yesterday near the Thames beach where a dog died of tetrotodoxin (TTX) poisoning. Photo / Alan Gibson

A formal health warning has been issued at Thames and Coromandel beaches after a dog poisoning confirmed that sea slug toxins had spread further than Auckland's coastline.

The Thames Coromandel District Council placed warning signs on beaches in the Firth of Thames yesterday. The signs, which urge supervision of pets and children, are in place from Tararu beach, just north of Thames, to Waikawau.

Buddy, a 12-year-old beardy cross, died soon after touching a sea slug on Tapu beach, 20 minutes north of Thames. She was the sixth dog to die from tetrotodoxin (TTX) poisoning.

Waikato District Health Board medical officer of health Dr Anita Bell asked parents to monitor where their children were playing.

Dog owners continued using Thames beaches yesterday, but Tapu beach was empty, even before Civil Defence warned people off the coastline because of a potential tsunami.

During August and September, at least 15 dogs showed signs consistent with TTX poisoning after eating slugs at Auckland beaches.

The possibility that sea slugs are not the only carriers of deadly tetrotodoxin is looking more likely the further from Auckland the poison is found, says the scientist in charge of the toxin tests.

Paul McNabb, Cawthron Institute's technical manager, said the latest dog death confirmed that the poison had spread over a wide area, making it harder to rule out other sea creatures being affected.

A map of dog poisonings prepared for the Auckland Regional Council shows the problem has surfaced at beaches around the Hauraki Gulf coast, from a few minutes south of the Whangaparaoa Peninsula, to Waiheke Island and Auckland City in the middle, over to the other side of the Firth of Thames on the lower Coromandel Peninsula.

A Cawthron report, prepared for the ARC, said studies had shown TTX could be produced by bacteria sometimes found in beach sediments.

Slugs from North Shore beaches were found to contain deadly amounts of TTX - enough that 0.25g of sea slug could kill a dog and 2g could kill a human - but it was not known how the slugs acquired the toxin.

The report said there was strong evidence that sea slugs and other creatures (including sea snails and puffer fish) collected TTX from somewhere in their food chain - without succumbing to the toxin themselves.

It recommended tests be carried out on beach sediment, kina, limpets, crabs, spotties and other sea creatures in the Auckland region to make sure they do not contain TTX.

Grant Barnes of the ARC said because the problem had spread beyond Auckland, it was not up to the council to pay for the tests.

POISON CHECKS ON DEAD PENGUINS

Dead penguins from previous seasons will be pulled from the deep freeze to see whether they have come into contact with rat poison.

The Department of Conservation has asked researchers at Massey University in Albany if it can take birds stored at their penguin research facility for Brodifacoum testing.

Tests by Crown scientists at Landcare Research found the blood-thinning poison in the livers of three out of nine little blue penguins that died in the Hauraki Gulf during the same months DoC was dropping Brodifacoum pellets.

Helicopters dropped three loads of cereal baits over Rangitoto and Motutapu Islands, finishing on August 7, as part of a project to create a rat-free sanctuary for rare birds.

Poison-drop project manager Richard Griffiths said the dead penguins weighed about half what a healthy penguin should and Auckland Zoo vets found they had died of starvation.

But the poison finding has surprised DoC, which wants to know if Brodifacoum was in penguin livers before the Rangitoto and Motutapu operation. Eloise Gibson