Digestive enzymes in carnivores
Digestive enzymes are produced primarily in the pancreas and released into the duodenum (first part of the small intestine) to help digest food coming from the stomach.
Their function in digestion
There are three main types of enzyme that help break down macronutrients in food:
1. Protease, to break down protein
2. Lipase, to digest fat.
3. Amylase, to process carbohydrates.
Most mammals produce amylase in the saliva, but dogs and cats do not. This reflects their expected diet of meat and organs from prey. Herbivores and omnivores have flat molars that crush and chew food, but the carnivore’s dentition is perfectly designed to capture and kill prey, and to rip and tear meat from bone. Carnivores don’t spend much time chewing; nor do they consume many carbohydrates, so there is no need for amylase in the mouth.
In addition, cells also carry enzymes called lysozymes. These are released upon cell death and help break down (digest) the contents of the cell, either for recycling (in a living body) or decomposition. Because the natural prey diet of canines and felines is consumed raw, these lysozymes may also contribute to efficient digestion of food.
When a carnivore kills a large prey animal, that carcass is likely to sit for a while (it takes about two weeks for a mountain lion to consume a whole deer). Wild canids commonly take advantage of the lysozomal process by burying parts of the carcass, and digging them up and eating them weeks later. In those scenarios, both internal lysozymes and various external organisms (bacteria, fungi) contribute to the food breakdown normally performed by the pancreas.
When heat destroys the natural shape of enzymes, they become non-functional. In dogs and cats that eat heat-processed pet food, those enzymes are absent; the pancreas must provide all the enzymes needed to digest the food.
In addition, commercial dry kibble is also much higher in carbohydrates than the carnivore’s natural prey diet. While cats’ and dogs’ pancreatic and intestinal tissues can and do produce amylases that are fully capable of digesting carbohydrates, the lack of salivary amylase reminds us that nature did not intend carbs to be their primary source of nutrition.
“Evidence strongly suggests that eating foods devoid of enzymes as a result of cooking, food irradiation, and microwaving, causes an enlargement of the pancreas and also stresses associated endocrine glands. In all of nature, the human pancreas is three times larger, as compared to total body weight, than that of any other animal. What is interesting, is that when mice are fed cooked foods, the ratio of their pancreas weight to total body weight becomes approximately that of a human’s. When they are switched back to a raw-food diet, their pancreas shrinks back to normal size. The most obvious conclusion is that the pancreas becomes enlarged, because it is forced to keep up a high digestive enzyme output.”
Research in animals has shown that the production of digestive enzymes is independent of diet. That is, animals are biologically programmed to produce specific types and amounts of digestive enzymes in response to food ingestion, regardless of what food they actually eat. Only major evolutionary shifts, such as changing from omnivorous to insectivorous lifestyles, affect these systems.
Our carnivorous pets have not, and cannot, adapt their digestive functions to processed diets, which, after all, have only been widely used for a few decades.
These facts and information just go to show that a cat’s digestive system is only designed to eat raw meat.
In addition to its dentition, the enzymes a cat possesses, show us that it should be eating a diet that is high in protein and low in carbohydrates.
From the time that the raw food enters the mouth, to the time it passes through the digestive tract, the biological make-up of the cat dictates what its natural diet should be to ensure the cat is happy, healthy and full of vitality.