Quotes of the Day

It was in the mid-1980s that Tom Lonsdale began making the observations that would eventually take over his life. Heading several veterinary practices in western Sydney, he noticed that the mouths of most of his cat and dog patients were in terrible shape - full of blood, pus and loose teeth. Periodontal disease was not a term he could recall hearing at vet school. He knew that many people, including vets, thought the natural state of cats' and dogs' mouths was repulsive. But something told Lonsdale that what he was seeing needed investigating.

Almost right away he had a theory. Talking with colleagues, he recalls, "We recognized that wild animals didn't have this problem . . . that gnawing on raw, meaty bones cleaned the teeth and kept the problem at bay." Lonsdale suspected that periodontal disease wasn't merely unpleasant for the animals; rather it was infecting other bodily systems and causing some of the illnesses for which Fido and Fluffy were being brought to the vet in the first place.

Lonsdale suggested to some of his clients that they change their pet's diet - from canned and dry food to such items as raw chicken carcases, kangaroo tails and whole rabbits. Within weeks, he says, the clients were reporting that "these near dead things had become sprightly again. They were gaining weight and their coats were developing a luster. All those non-specific ailments that we'd previously been puzzling over were disappearing. Animals no longer needed their arthritis pills, their corticosteroids for skin disorders, their flea treatments. We were destroying our client base. All the animals were getting better."

So where's Lonsdale now? Basking in glory as a giant of veterinary science? Well, no. In fact, he's an outcast, having recently been expelled from the Australian Veterinary Association for bringing the profession into disrepute. There's much to suggest that Lonsdale has become a victim of his own obsession. He quit practicing in 1992 to eke out a living researching and promulgating his theories. Ever since, he's hammered a simple message: commercial pet food - on which Australians spend $A1.3 billion a year - is bad for cats and dogs, which should be eating raw, meaty bones. Many vets have wearied of him; others mock him. The A.V.A. denies trying to silence Lonsdale. It says it canceled his membership in response to an e-mail he sent last year to - among others - all New South Wales state parliamentarians. In the message, Lonsdale called for action on his own "allegations of scientific and consumer fraud perpetrated upon an unsuspecting Australian public by an alliance of pet food companies and veterinarians."

The tragedy of the Lonsdale story is that his dietary message could be spot on. Periodontal disease is rife in cats and dogs, affecting 85% of those over three years old. Further, the A.V.A. acknowledges that a diet of mainly "soft foods" could "favor development" of periodontal disease and recommends giving bones at least once a week. A.V.A. national president Dr. Norm Blackman says that while Lonsdale's e-mail was "mischievous in the extreme . . . Tom has contributed quite a lot to veterinary science." Others go further. "I believe he's a visionary," says Dr. Richard Malik, the veterinary specialist at the University of Sydney's Post Graduate Foundation in Veterinary Science. Malik, who believes many vets are recommending the Lonsdale diet to their clients, backs Lonsdale's calls for a controlled trial to test the therapeutic effects of a bone-based eating plan.

At Lonsdale's urging, western Sydney breeder Leah Ryan switched her 10 to 20 collies from processed food to mainly meaty bones 17 years ago. The change, she says, slashed her vet bills from $A1,000 a month to zip: "I've not had a sick dog since." Lonsdale says a natural diet slightly increases the life span of most breeds of cat and dog, but more significant is the improvement to their quality of life. "Instead of being miserable they'll be healthy, then fall off the perch abruptly at the end."

Lonsdale won't be satisfied until bodies like the A.V.A. denounce commercial pet food and "admit they got it comprehensively wrong." He argues it's the A.V.A.'s alliance with pet food manufacturers that's stopping it from coming clean. Blackman dismisses this as "nonsense": only 0.4% of the A.V.A.'s annual income comes from manufacturers, he says, "and it's certainly not a driver of the recommendations we make about diet." Animals fed a pure Lonsdale diet, he adds, risk missing out on key nutrients and becoming constipated.

Lonsdale, who set out his theory in a self-published 2001 book, Raw Meaty Bones, gives the impression he could discuss pet food all day. "He's obsessive because he's been made a figure of fun," says a friend and former vet. "Being tiresome doesn't make him wrong." Lonsdale believes his ideas could have implications for human medicine: if this diet can reverse illness in animals, he says, "we should be finding out what the factors are" and seeing if they can be applied to people. No one expects the A.V.A. expulsion to do anything but embolden him. "He's on a crusade," says Sydney University's Malik, "which will end when he dies."

• Daniel Williams
• An Australian crusader against commercial pet food has fellow vets divided: is he a visionary or a crank?