Cat Food Questions

Start with the nutritional adequacy statement. In the US it tells you whether the food is "complete and balanced" for a life stage, based on AAFCO nutrient profiles or a feeding trial. If it says "for intermittent or supplemental feeding," it's a treat, not a meal.

Then read the ingredient list. Ingredients are listed by weight before cooking, so the first few make up most of the food. We look at the first five: how many are animal proteins, and whether the label names the animal ("chicken") or only a group ("poultry," "meat").

The guaranteed analysis gives protein, fat, fiber and moisture as fed. Foods with different moisture can't be compared directly, so we convert to dry matter. That's the protein number on our cards.

Last, the preservatives and other additives. When a label names a synthetic preservative such as BHA, BHT or ethoxyquin, we show it. Many labels say "preserved with mixed tocopherols" (a form of vitamin E), and some don't name the preservative at all. We report what the label says and leave the judgment to you.

AAFCO's minimum for adult cats is 26% protein on a dry matter basis, and 30% for kittens. Most dry foods are well above that. Cats need more protein than dogs or people, and they rely on nutrients that come from animal tissue.

Where the protein comes from matters as much as the number. Corn gluten meal or pea protein raise the protein figure on the label without adding meat. That's why our Ingredient score gives full points to named animal proteins and only one or two points to plant proteins such as corn gluten meal or pea protein. Each food's page shows its first five ingredients with their points.

Not automatically. Under AAFCO definitions, "meat by-products" are the clean parts of slaughtered mammals other than muscle meat, such as liver, kidneys, lungs, spleen, blood and bone. "Poultry by-products" include heads, feet and internal organs. Organs like liver are nutritious, and a cat eating prey eats them too.

What we look at is whether the label tells you which animal it came from. "Chicken by-product meal" names the animal. "Meat by-products" with no animal named comes from cattle, pigs, sheep or goats, but the label doesn't have to say which, so we count it as an animal protein with an unnamed source. More in What "Poultry By-Product Meal" Means in Cat Food.

Not by default. Grain-free foods usually replace corn, wheat or rice with peas, lentils or potatoes. Those are carbohydrates too, so the total carbohydrate may not go down.

Grain allergies are also uncommon in cats. In a 2016 review of cats with food allergies, the most frequent triggers were beef (18% of cats), fish (17%) and chicken (5%). Wheat and corn were 4% each. If your cat has itchy skin or stomach trouble, talk to your vet before you change foods.

Both can be complete and balanced, and neither is right for every cat. Wet food is about 75% to 80% water, so a cat eating it takes in more water overall, and many cats don't drink much on their own. Dry food costs less per day and can stay in the bowl.

One common belief doesn't hold up: ordinary kibble doesn't clean teeth. Only dental diets tested for plaque or tartar control, the ones with the VOHC seal, have shown an effect. Many owners feed a mix of both. Pettings covers dry food for now.

Not necessarily, but its weight needs watching. Many cats gain weight after neutering, mostly because they get hungrier, and spayed females may need fewer calories to hold their weight. Foods labeled for indoor cats often have fewer calories per cup.

With any food, weigh your cat every few weeks after surgery and adjust the portion. Your vet can tell you what a healthy weight looks like for your cat.

Cats can't make enough taurine on their own, so it has to come from food. A lack of taurine is known to cause heart muscle disease and damage to the retina. AAFCO sets a minimum of 0.10% taurine on a dry matter basis for dry food and 0.20% for canned food. Every food labeled complete and balanced for cats has to meet it. If you cook for your cat, work with a veterinary nutritionist. More in Taurine for Cats.

AAFCO's minimum for adult cats is 9% fat on a dry matter basis. Fat is the most concentrated source of calories, and the body needs it to absorb vitamins A, D, E and K. Cats also need arachidonic acid, a fatty acid from animal fat that they can't make in sufficient amounts. More fat means more calories per cup, which is worth knowing if your cat gains weight easily.

Most adult cats do well on two measured meals a day, and several smaller meals work too. Young kittens have small stomachs and usually eat three or four times a day until about six months. A bowl that's full all day makes it easy to overeat, so we'd measure the daily amount (it's on every food page) and split it.

A common rule of thumb is about 1 mL of water for every calorie the cat eats, counting the water in its food. A 9 lb cat eating around 200 calories a day needs roughly 200 to 250 mL, a little under a cup (7 to 8 oz). Cats on wet food get much of that from their meals. Cats on dry food have to drink it. Fresh water in a few spots, or a fountain, can help a cat that doesn't drink much.

Around 12 months for most cats. Large breeds such as Maine Coons keep growing for longer, so ask your vet when to switch. Kitten food has more calories, protein and minerals for growth. Make the change over 7 to 10 days, mixing in a little more of the new food each day.

Most foods call cats seven and older "senior." A healthy older cat doesn't need less protein. Research suggests many need as much or more, because digestion can get less efficient with age, especially after about 10. Some older cats lose weight and others gain, so keep an eye on the scale. If your cat has kidney disease or another condition, the diet is a decision for your vet. A yearly checkup is a good habit at this age.

Most adult cats can't digest lactose well, and cow's milk often gives them diarrhea or gas. Kittens make the enzyme that breaks lactose down, but most cats lose much of it after weaning. Water is all a cat needs to drink. Lactose-free "cat milk" is fine as an occasional treat, but it isn't necessary.

Raw meat can carry bacteria and parasites such as Salmonella, Listeria, E. coli and Toxoplasma, and these can make both cats and people sick. Advice on making raw feeding safer, for example by freezing the meat, isn't consistent between sources. If you're considering a raw diet, talk to your vet first. Pettings doesn't cover raw food.

Keep these away from your cat:

• Onions, garlic, leeks and chives, raw or cooked, including powders
• Chocolate and cocoa
• Alcohol and caffeine
• Raw yeast dough
• Grapes and raisins (poisoning is better documented in dogs, but vets advise avoiding them)

Xylitol, the sweetener in sugar-free gum, is very dangerous for dogs. Poisoning hasn't been reported in cats, but keep it out of reach anyway. Avocado mostly upsets the stomach; the pit and skin are the bigger risk.

If your cat eats something on this list, call your vet or the ASPCA Animal Poison Control Center right away.