Described by the manufacturer as a "biologically appropriate real-food kibble," Orijen pet food is processed using a proprietary low temperature (90ºC) steam-cooking procedure. The pet food is produced in Alberta, Canada and sold in 50 countries around the world.
In the 9 months since Orijen dry pet foods have been available in Australia, at least 40 cats have been stricken with a form of paralysis. Five of the cats had to be euthanized. The manufacturer (Champion Petfoods, Alberta, Canada), while recalling all outstanding Australian stock of its cat and dog foods, is pointing an accusatory finger at the government's import policies.
Because of the relatively mild heat treatment used in the production of Orijen foods, Australian import rules mandated that the pet foods be irradiated at a level of 50 kGray (5 Mrad) upon arrival. Champion claims that the high-dose radiation treatment is destroying vitamin A and promoting free-radical formation in the pet foods. According to the company, the resulting deficient diet is the cause of the symptoms that are being reported in Australian cats.
Champion cites its own tests of the effect of irradiation dosage on vitamin A depletion, and a small research study that was published last year to support its claims. The peer-reviewed study, published in Veterinary Pathology, examined the effect of an exclusive diet of gamma-irradiated food on a colony of 8 cats. The authors reported "... a possible association [of progressive hind limb ataxia] with the long-term feeding of cats exclusively on a gamma-irradiated dry diet deficient in vitamin A."
A spokesperson for the Australian government has pointed out, in reply, that no other imported pet foods brands have experienced similar issues. And a Sydney veterinarian was skeptical of the vitamin A deficiency argument when interviewed by The Sydney Morning Herald.
Is radiation-induced vitamin A depletion the explanation, or might the problem be something else? Champion Petfoods claims that paralysis syndrome has not been reported in any other country where Orijen is sold, and that only Australia demands irradiation. The company has decided to withdraw completely from the Australian market, and promises to continue its study into the effects of irradiation on Orijen dry pet foods.
Only time, and additional research, will provide some answers.