Newcastle man Art Ryan said his two Burmese cats, Missy and Jake, began losing the use of their limbs some months after being fed the expensive Orijen brand cat food.

Manufacturer Champion Petfoods recalled the food last year but insists it isn't the meat that's to blame for the paralysis.

Rather, the company says it's the Australian Government's apparently unique irradiation procedures that have caused the problems.

Champion says identical food is sold in many other countries, none of which has reported any cases of the strange nerve syndrome seen in Australia.

The company has pointed out a 2007 study linking so-called "leukoencephalomyelopathy" in cats to a diet of irradiated meat.

One theory is that gamma radiation, which reduces the food's nutritional value, destroys vitamin A, and the vitamin deficiency causes the nervous system problems.

The Government insists on irradiating the pet food at much higher levels than human food imports on the grounds that radiation will kill germs and protect Australia from foreign diseases.

Independent tests on the irradiated food have found "substantial reductions in vitamin A levels" and increased "production of oxidative by-products".

While the pet food company and the Government argue over the precise cause of the illness, cat owners are complaining that nobody will take responsibility.

Hamilton veterinary surgeon Chris McClelland said more than 60 cats had been affected in Australia by the strange nerve syndrome.

Several had died, but others had recovered, he said.

The syndrome appears to be confined to cats, with the dog version of the food causing no known problems.

Mr Ryan said he was heartbroken when his cats developed the illness.

"We started to feed them Orijen last September at the recommendation of our vet," he said.

"Next thing we were told the food was being recalled and there was this problem."

His cats remained symptom-free until late last month when their hind legs began to fail.

Mr McClelland said it was disturbing that the packaging had not been labelled to warn buyers it had been irradiated.

"I think there are good reasons to insist that irradiated food be properly labelled, whether it's for pets or people," he said.

An Australian Quarantine and Inspection Service representative declined to comment.