According to Nicholas Dodman, Director of the Animal Behavior Clinic, Cummings School of Veterinary Medicine, Tufts University
Don't Cry Wolf
Raw-meat diets, both homemade and commercially produced, have become popular with some dog owners. One rationale given is that wolves eat raw meat in the wild. This is true, but wolves live for only a few years. We hope our pets will live to a ripe old age , and that's where optimal nutrition comes in.
Watch for Bacteria
A significant concern with raw-meat diets is infection. Studies of commercial raw pet foods indicate that 20 to 44 percent are infected with salmonella. Contamination is potentially dangerous for both dogs and the owners handling the rations -- especially pets and people with compromised immune systems. Some raw food proponents say that domestic dogs can safely eat raw items because they have short gastrointestinal tracts and stronger stomach acid, but neither statement is correct. Or they say that raw-meat diets contain human-grade food, but even supermarket meat is often contaminated. In some studies, as many as 80 percent of raw chicken samples were found to be contaminated with salmonella or campylobacter, another pathogen. And we've done in-house studies at Tufts University in which home-prepared raw food was found to contain disease-causing bacteria such as E. coli and clostridium. Contrary to another common belief, freezing doesn't necessarily kill the bacteria present in raw meat.
Then there's the issue of bones. "Bones are safe as long as they are fed raw," say raw foodies. But again, this is not the case. Bones, raw or cooked, can cause intestinal laceration or obstruction and can fracture teeth.