A SERIES of mysterious cat deaths was caused by the government-mandated practice of irradiating imported pet food.

The Agriculture Minister, Tony Burke, has ordered the controversial sterilisation process, which has been in place for more than a decade, to cease immediately, following compelling overseas evidence that some cats can suffer fatal neurological damage after eating irradiated dry food.

Dogs do not appear to be affected by similarly treated food.

About 90 cats fell ill last year and 30 died before a Sydney vet, Georgina Child, made the link in November between the mystery illness and a brand of Canadian gourmet pet food called Orijen.

The manufacturer, Champion Petfoods, blamed the contaminated food on Australian quarantine regulations, which demand that pet food not cooked over a specified temperature undergo irradiation of 50 kiloGrays upon arrival in the country. Of the 60 countries Champion Petfoods exports to, only Australia makes irradiation compulsory.

The Australian Quarantine and Inspection Service and the company that carries out the process, Steritech, insisted at the time the irradiation process was harmless. A limited range of imported human foods, including dried herbs and some tropical fruits, are also irradiated before landing on store shelves, but at much lower levels than that mandated for pet food.

Mr Burke said the inspection service decided to act in response to international reports his department received only late last week. Work was being done in state and federal governments to see how safety standards for pet food could be improved.

“People expect that any treatments conducted on imported pet food will result in food that is still safe for pets,” he said.

Dr Child said the move was welcome but did not go far enough. The irradiation ban is not being extended to imported dog food, leaving cats with access to such food still at risk.

“We still don’t know why this problem is unique to cats, and we’re still not certain why some brands of pet food are affected by irradiation and not others,” she said. “What this does show is that all food that has been irradiated needs to be labelled, which isn’t the case at the moment.”

Sarah Oddy, of Dundas, who lost two cats after they were fed the Orijen pet food, said the ban was great news.

Champion Petfoods has set up a fund to disperse compensation for veterinary bills for all affected Australian cat owners.