The play on the proverb "Curiosity killed the cat" was a flippant use of humour for what is a sad necessity - the culling of feral cats, he said.

The State Government will announce a cat-eradication program today for Tasman Island, which will utilise the Curiosity cat bait and toxin. Curiosity was successfully trialled on Christmas Island last year to deplete feral-cat numbers.

"Feral cats pose a massive danger to all forms of Australian fauna," Dr Harry said.

"No cat, domestic or otherwise, should be allowed outside at any time in my opinion unless on a lead or housed in a suitable enclosure.

"The elimination of feral cats is not always a straightforward situation, as there is a balance in many areas of Australia between the fox population, the feral cat population and the rabbit population. A decrease in one may see substantial increases in the other.

"Therefore any program undertaken to eliminate feral cats should consider all consequences."

Dr Harry said it was important that any cat-eradication program executed culls in a humane way.

"With regards to the use of chemicals, these are no doubt a necessity and, provided they ensure a quick and painless death to the animal, then I have no problem with their use.

"As to the name given to this particular substance, I find it somewhat offensive. As a cat breeder for over 25 years I consider myself to be thoroughly responsible in the management of my cats and the use of such a derogatory name I find to be ill conceived, ill humoured and in a word, sick."

The contentious label also left a bitter taste for RSPCA Tasmania president Paul Swiatkowski who said he was "caught by surprise" when he heard of Curiosity, and was concerned cat-lovers would be offended.

"I believe in calling a spade a spade," he said.

"If you were advertising it, it would be deceptive advertising."