New research indicates that canned food may be better for your cat than dry food.  In order to understand this, here is a feline nutrition primer:

There are three main nutrients in all food: protein, carbohydrates, and fat. This pertains to cat food, dog food, human food, etc.  It is important to understand that different species have different requirements for the three nutrients.

Cats require more protein and fat than dogs or humans.  Cats are considered strict carnivores which means that they require animal protein and animal fat in their diets.  There are four amino acids (building blocks of protein) which are essential to a cat’s health that are not found in vegetable protein.  There are similar requirements for animal fat.  Cats cannot be fed a vegetarian diet and remain healthy.

Cats naturally metabolize protein easier than carbohydrates.  A cat’s metabolism is designed to use protein for energy, rather than carbohydrates.  Cats have not developed many of the metabolic pathways for processing carbohydrate diets that omnivores (such as humans and dogs) have.  They have reduced enzymes in the liver, pancreas and gastrointestinal tract that normally convert carbohydrates to usable energy.  Hence, excess carbohydrates are converted to fat in a cat’s body.

On the other hand an all-meat diet is also not healthy for a cat. Cats do need carbohydrates, just not a lot.  When a cat eats a mouse or other wildlife, her/she does not just consume the meat (muscle) of the wildlife, they also eat the bones, liver, heart, and the intestinal contents of their prey.  The intestinal contents of these animals usually contain plant material or fruit.  This is where cats get the small amount of necessary carbohydrates.

When comparing canned food and dry food (in general):

-There is more protein in canned food than dry food.

-There are fewer carbohydrates in canned food than dry food.

-Canned food has fewer calories than dry food.

Studies have shown that cats eat to fulfill their protein requirement.

This means that:

-A diet high in carbohydrates and low in protein will cause a cat to gain weight, since they will have to eat more of it to meet their protein requirement.

-A diet high in protein and low in carbohydrates (in restricted amounts) can help to prevent a cat from gaining weight.

-A diet high in protein and low in both carbohydrates and fat will help a cat lose weight.

Potential problems with feeding a cat only dry food (and no canned food) are:

-Weight gain

-Constipation

-Bladder problems

-Diabetes

So what is the best food for my cat?

-If your cat has any medical problems, please ask one of our veterinarians for a diet recommendation.

-If you are willing, the best diet is a premium canned food without dry food.

-Otherwise, we recommend feeding at least some canned food every day in addition to dry food.

    The average 10-pound adult cat should normally eat:

-One 6-ounce can per day

-Or, one 3-ounce can and ¼ cup dry food per day

-The allotted amount should be divided into two to four feedings per day.

-See our “Cat Fud for Dummies” handout on other recommendations for feeding.

What if my cat will not eat canned food? 

It is best to get your cat started on canned food as a kitten, since some mature cats will resist a change in their diet.  Many adult cats will refuse canned food; this is because the cat food manufactures spray tasty stuff on dry food to entice cats, causing them to be addicted to it.

Be persistent.  Put a small amount of fresh canned food in a separate bowl near your cat’s dry food every day.  After a while, your cat will accept it and try it.  Once your cat is eating some canned food, try decreasing the amount of dry food and increasing the amount of canned food.

The website www.indoorcat.org has a more detailed discussion on how to get your cat to eat canned food.