RAW MEAT DIETS
CUMMINGS SCHOOL OF VETERINARY MEDICINE
In addition to the nutritional imbalances of these diets, raw meat products are likely to carry bacteria (like any raw meat products we encounter at home or in restaurants). These diets pose a health risk, not only to the individual animal eating them, but also to other animals in the hospital and to our hospital staff.
Raw meat diets can be homemade from various recipes (eg, BARF or Ultimate diet). However, raw meat diets also are available commercially from a variety of companies. Commercial raw diets are typically frozen or freeze-dried but some can even look like regular dry food (eg, diets with a raw meat coating).
At this time, there are no scientific studies showing any health benefits of raw meat diets. However, studies show that there are significant risks to feeding raw meat diets. For example, one study demonstrated that all homemade and commercial raw food diets tested had multiple nutritional imbalances. Another study reported two cats that died of a blood infection from the same bacteria that was in their raw food. Other direct risks of raw meat diets include gastroenteritis (inflammation of the gastrointestinal tract, usually resulting in vomiting and diarrhea) and, for raw meat diets that contain bones, fractured teeth and gastrointestinal injury can occur.
In addition to these risks, recent scientific studies have shown that nearly all raw meat diets (whether commercial or homemade) are contaminated with bacteria, with between 20-44% of commercial raw food diets contaminated with Salmonella. Also, be aware that animals that eat raw meat diets can shed these bacteria in their feces (in one study, approximately half the dogs fed a single meal of contaminated raw food shed Salmonella in their feces for up to 7 days). Other bacteria found in raw meat diets include E coli 0157:H7 and Clostridia. These bacteria are a risk, not only for the animals eating the diets, but also for other pets and people in the household – this is particularly true for any people or animals who are young, old, or immune-suppressed.
Top Ten Myths about Raw Meat Diets
1. “Their benefits are proven”
No scientific studies have shown benefits of raw food diets. Their appeal is based on word of mouth, testimonials, and perceived benefits. For example, raw food diets may result in a shiny coat and small stools because they are generally high in fat and digestibility. However, these same properties can be achieved with commercial cooked diets without the risks of raw meat diets.
2. “This is what animals eat in the wild”
Wolves in the wild do eat raw meat (in addition to berries, plants, etc). However, the average lifespan for a wolf in the
wild is only a few years. Therefore, what is nutritionally “optimal” for a wolf is not optimal for our pets who we hope
will live long and healthy lives.
3. “Dogs and cats have short gastrointestinal tracts so won’t get infections from Salmonella in raw meat diets”
Dogs’ and cats’ gastrointestinal tracts are not shorter compared to people when viewed in proportion to their smaller
body size. Dogs and cats can become infected with Salmonella and other bacteria found in raw meat diets, just as
people can (especially young, old, or immunosuppressed individuals)
4. “Raw food diet ingredients are human grade”
Even meats purchased at the best of stores for people can be infected with bacteria so purchasing “human grade”
meat does not protect against the health risks of uncooked meats (would you eat raw hamburger?). Also, be aware
that the term “human grade” has no legal definition for pet food.
5. “Freezing raw diets kills bacteria”
Most of the bacteria found in raw meat diets can easily survive freezing.
6. “As long as bones are raw, they’re safe”
Bones, whether raw or cooked, can fracture dogs’ and cats’ teeth. Bone also can block or tear the esophagus,
stomach, or intestine.
7. “Cooking destroys enzymes needed for digestion”
All the enzymes that dogs and cats (and people) need for digestion are already in the gastrointestinal tract.
Therefore, additional enzymes from food are not required for digestion. In fact, enzymes are proteins so any enzymes
that are eaten get broken down by the body and have no benefit in the digestion process.
8. “Grains are added to pet foods as fillers”
Corn, oats, rice, barley, and other grains are healthy ingredients that contain protein, vitamins, and minerals; they are
not added as fillers. There is no benefit of potatoes, sweet potatoes, peas, or oatmeal compared to other
carbohydrate sources, unless the animal has certain specific health problems.
9. “Most commercial pet foods contain harmful ingredients”
By-products. By-products are the animal parts that Americans don’t typically eat, such as livers, kidneys, or lungs.
There are specific definitions for what by-products can and cannot include. For example, by-products must be the
clean parts of slaughtered animals and cannot include feathers, hair, horns, teeth, and hooves. Basically, by-products
are anything other than animal muscle. Note that some pet foods may actually list these ingredients (eg, duck liver,
beef lung) but these are really just “by-products.”
10. “If bones or chicken necks are added to raw meat diets, they’re nutritionally balanced”
Most homemade (and even some commercial) raw meat diets are extremely deficient in calcium and a variety of other
nutrients, even if chicken necks, bones, or egg shells are added. This can be disastrous in any animal but especially
in young, growing pets.
General dietary recommendations for dogs and cats*
- Feed a diet made by a well-known and reputable company – some criteria include:
- Employing at least one full-time nutritionist
- Having their own manufacturing plants
- Conducting nutritional research so that continued improvements are made to their diets
- Maintaining good internal quality control standards (eg, ingredients, end product, shelf life, accountability)
- Feed a diet that has undergone Association of American Feed Control Officials (AAFCO) feeding trials – not just
formulated to meet AAFCO profiles. Pet foods can be established to be complete and balanced in one of two ways:
1} By formulation to meet the levels established by the AAFCO or 2) by AAFCO feeding trials. A diet that is only
formulated contains nutrients in amounts that meet AAFCO minimums but the diet has not undergone feeding trials.
Therefore, unforeseen problems with bioavailability or nutrient interactions could arise. Feeding trials provide better
assurance that the food meets a dog’s or a cat’s requirements. Although AAFCO feeding trials have their limitations,
they should be a minimum level of assurance. When feeding trials have been performed, the label will read, “Animal
feeding tests using AAFCO procedures substantiate that Brand X provides completed and balanced nutrition for
growth (or maintenance).” If the food is only formulated to meet requirements, the label will read, “Brand Y is
formulated to meet the nutritional levels established by the AAFCO Dog (or Cat) Food Nutrient Profiles … ” Beware of
any over-the-counter diets that do not have either of these two statements (this means the diet is not complete and
balanced). Note that therapeutic diets sold by veterinarians designed to help manage certain diseases may have a
statement that reads “for intermittent or supplemental feeding only.” These diets should be used under the
supervision of a veterinarian.
*Note that dogs and cats with medical conditions may benefit from dietary modifications
Lisa M. Freeman, DVM, PhD, Diplomate of the American College of Veterinary Nutrition
Clinical Nutritionist, Tufts Cummings School of Veterinary Medicine
For further information visit www.tufts.edu/vet/nutrition/faq