South Australia's Kangaroo Island has embarked on an ambitious program to eradicate all cats, including pet cats, within the next 15 years.

It is estimated there are between 3,000 and 5,000 feral cats on Australia's third largest island.

The new eradication program, funded by the Federal Environment Department, has begun collecting data on the location and habits of feral felines, so future culling plans can be put in place.

But Kangaroo Island Mayor Peter Clements plans to phase out domestic ownership too.

"We have to reach a point where we don't have any cats on this island," Cr Clements told Landline.

"The feral cat is an apex predator. It is ruining our species here on the island and we are totally committed to eliminating all cats."

Feral cats 'amazing, highly evolved predators'

Kangaroo Island already imposes some of the nation's most stringent cat ownership bylaws; all pet cats must be registered, desexed and microchipped.

With no feral foxes, rabbits or deer on the island, feral cats do not have predators or competitors for food, according to the feral cat project coordinator Pat Hodgens.

He said the cats were hunting and killing birds, penguins, small mammals and reptiles.

"I think they're an amazing animal, highly evolved, amazing predators," Mr Hodgens said.

"I don't hate cats. I guess I love native species more," he said.

The wild cats also spread two diseases — toxoplasmosis and sarcosporidiosis — to a range of other animals, including sheep.

Up to 70 per cent of sheep meat from Kangaroo Island is affected by sarcosporidiosis. ( Landline: Prue Adams )

Toxoplasmosis can lower fertiltiy in farm animals, while sarcosporidiosis leaves cysts on the muscle tissue of sheep, cattle and pigs, leading to a downgrading of the meat at the abattoir.

Kangaroo Island farmer and Natural Resources Management member Richard Trethewey said meatworks "kill sheets" showed as much as 70 per cent of the island's sheep meat was affected by sarcosporidiosis.

"Feral cats have been a big issue in terms of sheep production on Kangaroo Island for many years," Mr Trethewey said.

"Significant production losses have been caused by feral cats, and this is of course in addition to the damage they do to our wildlife," he said.

Program managers prepared for backlash from cat lovers

The cat eradication program is part of a Federal Government plan to cull cats on five islands — Christmas, Bruny, French, Dirk Hartog and Kangaroo islands.

The ABC crew films Pat Hodgens as he checks a night camera on Kangaroo Island. ( Landline: Prue Adams )

Mr Hodgens said once the data-collecting phase of the program was over, a range of tools and processes would be employed to humanely cull cats.

Grooming traps will soon to be trialled, whereby cats passing a sensor will be squirted with a toxin that they lick off their coat.

A detector dog has been trained to seek out cats in inaccessible bushland, so the cats can later be euthanased.

Scientists also plan to build a barrier fence across the narrowest part of the island to eradicate cats in the smaller eastern section of Kangaroo Island, before concentrating on the larger tract to the west.

Despite two council surveys showing support for cat management, Mr Hodgens expected a backlash from cat lovers.

"It's a very public program so we are going to get criticism, absolutely," he said.

"We know that and we are prepared for that.

"But [we're] following very strict ethical humane practises.

"What we are doing has already been signed off on at a state level and also a federal level, so we are abiding by everything that we need to do."

Watch Landline's story on Kangaroo Island's cat eradication program on ABC TV at midday on Sunday.