Raw diets are a contentious topic among cat lovers and veterinarians. What is not disputed is that cats are obligate hypercarnivores who must consume meat in their diet. But why is it that cats can eat raw meat but humans can’t?
Humans have adapted to eating cooked meat which is easier to digest and allows the body to obtain more nutrients. However, we can eat some raw meat such as steak tartare, beef carpaccio, and sushi. But, the meat must be prepared meticulously to reduce the risk of food poisoning or parasitic infection. Pregnant women and immunocompromised people should not eat raw meat.
Cats can and do catch infections from raw meat that can potentially be spread to humans. But healthy cats have better resistance to pathogens in raw meat than humans. There are a number of physiological differences between cats and people.
The gastrointestinal tract starts from the mouth, where the teeth grind meat, organs and bones into smaller pieces. The tongue has backward-facing papillae (spines) made of hardened keratin to rasp meat from the bones of their prey. When the cat swallows, food passes into the esophagus where wave-like contractions (peristalsis) move food into the stomach.
The stomach is a hollow organ that stores, churns and breaks food down into a chyme with the help of stomach acid. Chyme passes out of the stomach through the pyloric valve and into the small intestine where enzymes and bile continue to break down and absorbs food.
Undigested food passes into the large intestine, where water and salts are removed from the remaining food. The leftover waste (feces) leaves the body via the anus.
What makes cats able to eat raw meat?
Cats have evolved to digest the raw meat, organs and bones of small prey such as birds and rodents. Their wild ancestors didn’t have the luxury of cooking meat, therefore their bodies had to be able to tolerate raw food without making them sick.
Gastric (stomach) acid is an acidic digestive fluid produced by parietal cells. One small study found the average pH of healthy cats to be 1.6 ± 0.3. The highly acidic nature of stomach acid allows the stomach to break down meat and bone and acts as a disinfectant to kill pathogens.
The small intestine is located between the stomach and the large intestine and is responsible for absorbing nutrients from food. The feline small intestine is notably shorter than that of the human intestine and has a rapid transit time, which means pathogenic organisms have less time in the small intestine to take hold.
Omnivores, which includes humans, have a medium length small intestine while herbivores have a long gastrointestinal tract with fermentation chambers.
Healthy cats have a natural resistance to gastrointestinal diseases such as E. coli, listeria and Salmonella. Kittens, seniors and cats with underlying health issues are at the greatest risk. Cats can be carriers, which means the cat does not show clinical signs of disease, but can carry and transmit the pathogens via their feces and saliva.
Should cats eat raw meat?
Cats aren’t immune from foodborne pathogens, but they generally remain asymptomatic to food poisoning as long as the meat is fresh and handled properly. These risks must be weighed up as some have the potential to infect humans. A home-prepared raw diet must be nutritionally complete to ensure the cat gets all the nutrients he or she needs.
The decision to feed raw meat must be discussed with the cat’s veterinarian, or better still, a board-certified veterinary nutritionist. There are many factors to consider including the health of the cat, therapeutic diets the cat requires to manage or treat a disease, and the immune status of the humans in the home. Raw meat is not recommended if the cat or people in the home are immunocompromised.
- Avoid game (wild-caught meat): Some wild-caught meats such as kangaroo and rabbit can be contaminated with lead fragments, which is extremely toxic to cats.
- Mincemeat at home: Ground/minced meat can harbour more bacteria. Bacteria present on the surface of the meat are ground into the meat as it is minced, and can rapidly multiply. If you do want to give your cat minced meat, I would suggest buying steak and mincing it yourself at home and serving immediately.
- Don’t rinse meat: People are in the habit of rinsing meat, mainly raw chicken before processing; however, this is not a safe practice. Rinsing spreads bacteria to nearby surfaces. Instead, dab the chicken with a dry paper towel.
- Buy human-grade meat: Find a good quality butcher to supply your meat. Never buy meat if the packaging is bulging.
- Wash your hands: ALWAYS wash your hands with hot, soapy water before and after handling raw meat.
- Leave food out for 20 minutes: Bacteria quickly multiply in a warm environment, so remove and dispose of any uneaten meat after 20 minutes.
- Don’t prepare raw meat and fruit/vegetables on the same board: Have separate boards for raw meat and other food such as fruit and vegetables.
- Washing up: Wash your cat’s food bowl, chopping board and other utensils in hot, soapy water or better still, the dishwasher.
- Storage: Never store cooked and raw meat on the same plate. Store raw meat on the bottom shelf of the refrigerator so it can’t drip juices onto prepared meat. Always ensure raw meat is adequately wrapped in the fridge to avoid cross-contamination.
- Freeze raw meat: Toxoplasmosis can infect the muscle tissue where it forms a cyst. Freezing for a minimum of three days can inactivate cysts.
- Temperature: Store raw meat below 5C.
- Follow use-by dates: Always feed before the use-by date, and check with your butcher how long the meat can be refrigerated. As a rule, store chicken or mince for 1-2 days, and beef for three days (unless a use-by date stipulates otherwise).
- Safely defrost meat: Place in the refrigerator the night before to slowly defrost. Never defrost meat at room temperature.
- Cleaning litter trays: Always wear gloves when cleaning out trays and dispose of feces in the outside garbage bin (do not flush down the toilet). Remove solids twice a day, and empty, disinfect and replace with fresh litter once a week. Pregnant women or immunocompromised people should not clean litter trays.