This article is from the General Cat Care FAQ, posted to rec.pets.cats newsgroup. Maintained by Cindy Tittle Moore with numerous contributions by others.
Premium cat food
Although more expensive than average brands, these foods are often better for your cat. They are low-bulk, which means that cats will digest more of the food, thus eating and eliminating less. They contain little or no dyes, which can be important if your cat vomits regularly (easier to clean up); probably also good from a diet viewpoint.
Examples of these kind of brands include (but are not limited to) Hill's Science Diet, Iams, Wysong, Nature's Recipe (Optimum Feline), and Purina (One). These foods are also beneficial for the cats coats and many readers have attested to their cat's silky fur and good health on these diets.
Cat food composition
The Guaranteed Crude analysis provides more nutrition info than you can get on the vast majority of human foods. If you want more, ask the vendor. E.g. Purina is 800-345-5678. Any major commercial cat food is formulated with either natural ingredients (including meat byproducts which supply nutrients to cats that meat itself doesn't since cats in the wild eat the whole animal) or are supplemented with the required nutrients to make them balanced diets for cats.
Canned foods contain quite a bit of water. It is expensive. Tartar build-up may be a problem. Smell (of the food, the cat's breath, or the cat's feces) and gas may be a problem. The food can spoil quickly. The dishes will have to be washed every day. Stools will be softer. On the other hand, cats that have medical conditions requiring higher water intake may benefit from the water in these products.
Cats will require more water on this kind of diet, but tartar-buildup may be lessened as a result of crunching on the kibble. Generally less expensive and less smelly. Dishes will remain clean and food will not build up nor spoil quickly. Stools will be firmer.
These are "soft kibble". The benefits are difficult to ascertain. They are more appealing to humans than anything else. There is no anti-tartar benefit and not much difference from canned food. They are fairly expensive. A lot of dye is typically used, which makes vomit very stain prone. Some are actually bad for your cat: proylene glycol found in these products (as a preservative) can damage red blood cells and sensitize the cats to other things as well. (Source: August 1992 edition of Cats Magazine.)
Many snack products are out there for cats. Most are fine as supplemental feeding, but of course they should never take place of regular food. Try to use treats that are nutritionally balanced so as to minimize any disruption in your cat's overall diet. Treats like dried liver, which are not balanced food, should be used sparingly. In addition, these products can be useful in training.
Most adult cats are lactose intolerant and drinking milk will give them diarrhea. Otherwise, milk is a nutritious snack.
Cream is even better than milk -- most cats can handle the butterfat just fine and it's good for them. A small serving of cream will satisfy the cat more than a saucer of milk and will contain less lactose.
Check Frazier's The New Natural Cat. She gives a number of recipies and general information on making your own cat food and on what foods are good for sick cats.
A number of cat books contain recipies for making your own kitty treats. These can be fun to make and give to your cat.
It is a poor idea to feed cats table scraps or food from your own meals. First, table scraps do not meet your cat's nutritional needs and only add unneeded calories or undigestibles to its diet. Second, you risk having your cat become a major nuisance when you are eating. Stick with prepared cat treats. Any food you give it should be placed in its food dish, or you can give it treats as long as you are not eating or preparing your own food.
That said, there is a pretty wide variety of food that cats will eat and enjoy. Rec.pets.cats abounds with "weird food" stories ranging from peanut butter to marshmallows.
Cats benefit from some vegetable matter in their diet. When devouring prey, the intestines, along with anything in them, will also be eaten. Many owners grow some grass for their cats to munch on, both for a healthy diet, and to distract them from other household plants!
In general, seeds that are OK to grow and give to your cats (but do not use treated seeds, identifiable by a dyed red, blue or awful green color):
* oats (cheap, easy, big)
* wheat (not wheatgrass)
* Japanese barnyard millet,
* rye (but beware of ergot, which is a fungal infection and produces LSD-like chemicals),
* ryegrass (annual ryegrass is cheap and easy to grow, but small),
* alfalfa sprouts or bean sprouts in SMALL amounts (these have anti- protein compounds that reduce the protein value of other things fed to the animal -- or human!)
Seeds that are NOT okay: sorghum or sudangrass, which have cyanogenic glycosides, and can cause cyanide poisoning. These are commonly found in bird seed and look like smallish white, yellow, orangish, or reddish BB's, or the shiny black, yellow or straw colored glumes may be intact.
Dog food is not suitable for cats since it does not have the correct balance of nutrients. Cats need much more fat and protein than dogs do and will become seriously ill if fed dog food for an extended period of time.
"Ash" in cat food is the inorganic mineral content left over when the organic portion has been removed. It generally consists of potassium, magnesium, and sodium salts, along with smaller amounts of other minerals. It used to be thought that the total "ash" content of food contributed to FUS, but recently, attention has focused on magnesium as the culprit. Many commercial foods now list the magnesium content as a separate item in the list of nutrients on the bag, box, or can.
You can feed your cat in one of two ways. One is to put down a set amount of food at specific times of the day. This is necessary if the food will spoil (canned food, for example) or if your cat will overeat. Some cats *do* overeat, do not be surprised if this is your situation. Put it on a fixed schedule to avoid weight problems. Do *not* assume a cat will only eat what it needs: if it starts putting on too much weight (check with your vet), give it two feedings a day, putting down half the recommended daily amount each time. The other method (called "free-feeding") is to leave food available all the time. The food must be dry to avoid spoilage. There is no preference between the two; it will depend on your cat and the food you give it.
Special Diets (incl. vegetarian diets)
You may need to change your cat's diet for any number of reasons. Often, you will find that your cat refuses the new food. Don't worry. Leave food out and keep it fresh until your cat is hungry enough to eat it. Your cat will not be harmed by several days of low food intake: as a carnivore, it is biologically adapted to going without food for several days between kills. If you give in to its refusal to eat the provided food, your cat has just trained *you* to feed it what it wants.
If you need to decrease the total amount of food the cat normally eats, the best way to do this is to reduce the amount of food gradually. This way, you don't have an upset cat after its meal.
If you have a cat that bolts its food down (and throws it back up), you can slow its eating down by placing several one to two inch diameter clean rocks in its food bowl. Picking the food out will slow it down. Be sure the rocks aren't so small it could eat them by accident.
If you have multiple cats, and one of them requires special food (from medical to weight-loss diets), then you must go to a fixed feeding schedule to ensure that that cat not only gets the food, but doesn't get any other food. If you have been free-feeding, switch them over. Don't put out any food the first morning; that evening, put out the dishes and supervise the cats. They will most likely be hungry and eat most of the food. Take the dishes up after 1/2 hour or so and wait until morning. Thereafter, remain on the morning/night- or even just night- scheduled feedings and your cats will adapt quickly enough. If you have trouble with one cat finishing quickly and going over to feed on other cats' food, you will have to put them in separate rooms while feeding.
As for vegetarian diets, cats require the aminosulfonic acid taurine, which is unavailable in natural vegetable except for trace concentrations in some plant sources like pumpkin seeds; not enough to do a cat any good. Lack of taurine can cause blindness or even death by cardiomyopathy. There are also a few other similar nutrients, such as arachidonic acid (a fatty acid only found in animals), but taurine is the most widely known.
Some small manufacturers claim to have produced synthetically-based supplements that when combined with an appropriately balanced all-vegetable diet will provide the complete nutrition required by cats.
No one has been able to find studies which demonstrate that cats which eat such a diet over the long term stay healthy.
Some references (books, articles, and mail-order companies) are included at the end of the Resources FAQ.