By Kate O'Rourke
Posted Jan. 1, 2005
In recent years, feeding dogs raw meat has become increasingly popular. The trend, however, has sparked health concerns, because of the risk of foodborne illnesses in pets as well as the public health risks of zoonotic infections. Now, a new study that identifies potentially harmful bacteria in 21 commercial raw meat diets bolsters these concerns.
"This has some potential public health concerns for both the animals being fed these diets and their human owners," said Dr. Rachel Strohmeyer, a researcher at the Animal Population Health Institute, Colorado State University. She presented her findings at the annual meeting of the Conference of Research Workers in Animal Diseases held in Chicago in November.
Proponents of raw meat diets say it improves dogs' performance, coat, body odor, teeth, and breath. While high-performance dogs, such as racing Greyhounds and sled dogs, have been fed raw meat diets for years, the trend to feed raw meat to companion dogs is new.
Because of this trend, and because the safety of these raw diets has received limited attention, Dr. Strohmeyer tested 21 commercially available raw meat diets, two dry dog foods, and two commercial canned dog foods for non-type specific Escherichia coli, Salmonella spp, and Campylobacter spp. The researchers purchased diets of beef, lamb, chicken, and turkey in four months, trying to space the purchasing times far enough apart so that they came from different lots. Three samples from each product underwent bacteriologic culturing each time.
The researchers did not find Campylobacter spp in any of the foods, but non-type-specific E coli was isolated from all raw meat products. Ten of the raw products contained S enterica. "It is really important to note that 99 percent of raw meat samples were contaminated with aerobic bacteria, and 79 percent had gram-negative, probably enterica, contamination," Dr. Strohmeyer said.
The scientists also found non-type-specific E coli in a few of the samples taken from the dry food, and believe post-processing contamination is to blame for these results.
"There is a greater apparent risk to animals and humans from feeding a raw meat diet," Dr. Strohmeyer commented. "I really do not think that there is any advice we, as veterinarians, can give to improve safety. You can give basic food safety guidelines like hand washing, cleaning surfaces, and bowls, etc., not letting the food sit out for extended periods of time. I just think that it would be a disservice for a veterinarian to give any recommendation for the safety of dogs and their owners (except to not feed raw meat to pets). Bacteria are not the only health concern, there are also parasites and protozoal organisms that can be transmitted in raw meat, even meat labeled fit for human consumption."
Other veterinarians, including Dr. Jeffrey LeJeune, a food safety molecular epidemiologist and microbiologist at The Ohio State University, agree that pets should not be fed raw meat. This may be a hard sell, however, to some clients.
"From my own clinical experience, owners that feed raw (meat) pretty much have their minds set that they are going to feed raw," Dr. Strohmeyer said. She thinks clients who are thinking about feeding raw (meat), however, can be swayed fairly easily, just by basic education.