Enzymes are proteins in the body that help chemical reactions proceed normally. There are thousands of enzymes in the body, but only two main types: digestive and metabolic. Metabolic enzymes are involved in every process in the body, from energy production to cell repair. Digestive enzymes work exclusively in the gastrointestinal tract to help digest the food animals eat.
In mammals, the salivary glands and pancreas provide digestive enzymes to help break down food. In herbivores and omnivores, saliva contains amylase, an enzyme that breaks starch down into simple sugars. You can test this yourself by chewing a saltine cracker without swallowing; eventually it will taste sweet. (Don't forget to swallow when you're done with the experiment!) Carnivores, however, don't produce salivary amylase; their natural diet contains mostly protein and fat, and very little starch.
The pancreas, a large gland sitting along the small intestine opposite the liver, is the main provider of digestive enzymes. It makes protease, to break down protein; lipase, to digest fat; and amylase, to digest carbohydrates. When food leaves the stomach, the pancreas secretes bicarbonate to neutralize the stomach acid, and digestive enzymes, which get churned into the food and break it down so the intestines can absorb the nutrients.
In addition to pancreatic enzymes, there are other natural helpers for digestion, which makes sense, since it's such a crucial process. Every living cell contains enzymes, and some of the enzymes within each cell are capable of "self-digestion." To prevent them from digesting the cell while it's still alive, they are packaged inside bundles called lysosomes. When the cell dies, these packets rupture and the enzymes inside destroy and digest the cell's "remains." Some of us have seen this exact process occur in the refrigerator when a bag of lettuce gets forgotten in the bottom drawer. A few weeks later, what you'll find in that drawer is a bag of brown liquid - the lettuce has completely digested itself into water and a few other elements. Raw foods, like fresh meat, do the same thing; it's a natural process of decomposition. On the other hand, cooked foods - in which the natural enzymes have been destroyed by heat - tend to get moldy. (Some fresh foods, like fruit, also get moldy just to make life interesting!)
Because heat destroys ("denatures") the natural shape of enzymes, they become nonfunctional. In dogs and cats that eat processed pet food, the pancreas is left without any help and must provide all the enzymes needed to digest the food. The pancreas is a sensitive little organ, and it doesn't like being overworked. So it makes good common sense to do all we can to keep the pancreas happy. Adding digestive enzymes to our pets' food is an easy way to do this.
Digestive enzymes for pets typically come in powdered form, making it easy to sprinkle on or mix with wet food. For most pets, the best enzymes come from plants or fungi (yeast), because they can survive the trip through the stomach's seriously acidic environment (however, some pets do better on pancreatic extracts). Make sure the enzymes you choose contain at least protease, lipase, and amylase (many also contain cellulase, which is a bonus if the food contains fibrous vegetables or grains).
Here are our best digestive enzyme products:
- Only Natural Pet Vital Digest
- Animal Essentials Plant Enzymes & Probiotics
- Prozyme Plus
- In Clover OptaGest Digestive Aid
- Pet Naturals Digestive Support for Cats and Dogs
- Bio-Zyme (pancreatic extract)