Bacteria and Raw Pet Food

Bacteria and Raw Pet Food

Author: Audrey Blanco

The microscopic world around us is so vast that if every living thing and every non-living object were to suddenly disappear, except for the microscopic life, you would still be able to see the outline of everything that was gone. That's a lot of microscopic life. Without these organisms every other living being would soon die.

As human beings we depend on our bacteria to perform many biological functions for us and to protect us from disease. "Protect us from disease?" you may say, "I thought bacteria caused disease!" Well some do, but there is a balance that we have to achieve in our bodies.

The billions of bacteria that live with us (and our pets) in harmony are called our normal flora. Normal flora is essential to our health in several different ways:

  • They protect us from invasion by disease-causing bacteria by using up the nutrients that disease-causing bacteria need.
  • Their waste products are sometimes toxic to disease-causing bacteria, thus preventing their growth.
  • They stimulate our immune system to keep them active.
  • They help to digest our food and releases the nutrients that our bodies need.
  • They produce vitamin K and certain B vitamins in our intestines. This function is performed by billions of E. coli bacteria in our intestines. Yes, E. coli can be good.

Bacteria That Can Make You Run


Salmonella organisms are found in the intestines of virtually all animals, including poultry, reptiles, livestock, rodents, birds and humans. Animal-to-animal spread and Salmonella-containing animal fed maintain the reservoir. The most common sources of human infection are poultry, eggs, dairy products, and foods prepared on a contaminated work surface. Humans are exposed to Salmonella bacteria on a regular basis, although most of us have never suffered disease due to exposure. Our main defense against disease with Salmonella is our stomach acid. Salmonella is very sensitive to and dies easily in the presence of acid. A dog's stomach is much more acidic than ours, so they have even more protection. Human beings need to consume a whopping dose of Salmonella in order to get sick, as most organisms are killed in the stomach. The number is somewhere in the order of 100,000,000 Salmonella bacteria. These amounts are not usually present in food that has been handled properly. Purchasing your raw meat from a reputable source should mean that it was kept at appropriate temperatures before delivery to you. Proper storage of meat after purchase should eliminate any further problems.

Symptoms generally appear within 6 to 48 hours after exposure and include nausea, vomiting and non-bloody diarrhea. Fever, cramps, muscle aches and headaches are common. Symptoms usually disappear within 2 to 7 days without treatment. About 10 percent of affected patients go on to develop complications that may require treatment. These patients are usually ones with a weakened immune system, the elderly or children.

Children are more susceptible to disease caused by Salmonella in part because their immune systems are not as well developed as adults and in part because they tend to have poorer hygiene than adults. Encourage children to wash their hands after handling any pet and discourage doggy kisses, if you like - but the likelihood of 100,000,000 Salmonella bacteria being present in a doggy kiss is virtually non-existent.


Campylobacter infections can be acquired from consuming contaminated food, milk or water. Eating undercooked, contaminated poultry products causes over half of all Campylobacter infections in humans. The disease caused by this organism is not as serious as from Salmonella, and usually resolves without treatment. Once again, the severity of the disease is determined by the number or bacteria consumed. Campylobacter is the most common cause of bacterial food poisoning.

Symptoms of the disease include diarrhea, malaise, fever and abdominal pain. Symptoms usually resolve within a week without treatment and long-term complications are extremely rare.

I find it interesting that the domestic dog, as well as the chicken, carries Campylobacter in its intestines normally. This means that many of us who share our lives with dogs have in fact been exposed to these bacteria on a day-to-day basis. It is also interesting that I have not heard of a single case of Campylobacter disease contracted from exposure to the family dog, although I understand that they have been reported in the literature.

E. Coli 0157-H7

Since the incident in Walkerton, Canada, the mention of E. coli tends to strike fear into people's hearts. There are thousands of strains of E. coli. E coli 0157-H7 is only one strain, and a fairly rare strain at that. It is not carried by chickens, but by cattle and other large grass-eating animals. Very few cattle carry these bacteria and then only in their intestinal tract, not in the muscle meat. Slaughterhouses check for these bacteria, which is why there is the occasional recall of ground beef. The reason that ground beef is the major culprit is that sometimes intestinal contents contaminate the muscle neat during the slaughter process. The surface of the muscle meat becomes contaminated. Then during grinding of ground beef, the entire batch can become contaminated. Unpasteurized fruit juices from orchards that may have been contaminated with cattle feces can also be a source.

E. coli 0157-H7 causes disease that ranges from fairly mild in most healthy adults to extremely serious in up to 10 percent of children under the age of 10. Disease can be caused by ingestion of fewer than 100 bacteria. Symptoms range form mild diarrhea to extremely bloody diarrhea with severe abdominal cramps. In a small percentage of children renal failure and death can occur.

The key to avoidance of disease is to cook all ground beef for human consumption to a well done state. Avoid cross contamination of all surfaces in your kitchen by always using a different cutting board for meat products than for vegetables and other goods that might be served raw. The same goes for cross contamination of knives and other utensils.

We tend to be clean in our own homes while preparing our pet foods. A rendering plant does not necessarily share our views. I have more concerns personally about what is present in commercial pet foods, than about anything I prepare with love at home.

Cleaning Up

A final word about cleaning up after preparing raw food. Please try to eliminate the amount of cleaning products you use that are marked "antibacterial". These products are harmful to the environment. They kill our normal flora that protects us, thus weakening our own immune systems. They cause bacteria to mutate and give them more protection to antibiotics and antibacterial products. Losing the war with bacteria by helping them to become more and more resistant to antibiotics is the one thing that does scare me. Doctors are partially responsible by over-prescribing antibiotics.

We consumers are also partially responsible. Antibacterial soaps are not necessary. Wash your hands after food preparation, with a regular soap and water. This is enough to remove any bad bacteria and leaves the good ones intact. A suitable household disinfectant is regular household bleach, mixed 1 part bleach to 4 parts water. This kills bacterial instantly and gives them no chance to mutate. It is also not harmful to the environment. Bleach or Lysol products for bathroom cleaning are O.K. - all of the common sense rules apply. Use stainless steel or glass bowls for pet foods, they are non-porous and easier to clean. The same goes for cutting boards. Wood is porous and may trap bacteria. Do not use the same cutting board for meat as for vegetables. Hot, soapy water is sufficient for the clean-up of dishes, and the dishwasher is even better. Bleach your cutting boards if you have no access to a dishwasher.

Relax and know that you are doing the best for your pet, and that with a little common sense you and your family are not likely to catch anything from the preparation or feeding of raw pet foods.


Murray, Rosenthal, Kobayashi, Pfaller, Medical Microbiology, Mosby, Inc. 1998; Nester, Roberts, Pearsall, Anderson, Nester's Microbiology-A Human Perspective, McGraw-Hill, 1998; Audrey Blanco is a Registered Technologist at the Department of Clinical Microbiology at Royal University Hospital, Saskatoon, Saskatchewan.