Cat Food: How to Choose the Right Food for Your Cat

Cats are obligate carnivores. They need nutrients that only animal tissue supplies, and that shapes every food choice you make.

What cats need from animal food

• Taurine. Cats can't make enough of this amino acid. Too little causes heart disease (dilated cardiomyopathy) and eye damage. It's found in meat, especially heart, and complete cat foods add it.
• Arachidonic acid. An essential fatty acid that cats must get from animal fat.
• Preformed vitamin A. Cats can't turn beta-carotene from plants into vitamin A. Liver and fish oils supply it.
• Niacin (vitamin B3). Cats need more than many other animals and can't make enough from tryptophan.
• Vitamin D. Cats can't make enough from sunlight, so it has to come from food.

A food labelled "complete" already covers these. If you cook for your cat at home, a vet or veterinary nutritionist should check the recipe.

Wet, dry, raw and freeze-dried

Wet food

• About 75 to 85 percent water, which helps cats that drink little
• Usually higher in protein and lower in carbohydrate than dry food
• Most cats like it, and it suits cats with urinary problems
• Costs more per calorie and goes off soon after opening (cover it and keep it in the fridge)

Dry food

• Cheap, easy to store and handy in puzzle feeders
• Only about 10 percent water, so a cat eating only dry food must drink more
• Easy to overfeed, which is a common route to weight gain
• Dental benefit is small at best

Many owners mix: measured dry food in a puzzle feeder, plus wet meals.

Raw food

Raw meat can carry Salmonella, E. coli and other bacteria that make cats and people ill, and home-made raw diets are often unbalanced. WSAVA has published material on these risks. Talk to your vet before you try it, and take extra care if children, older people or anyone with a weak immune system lives with you.

Freeze-dried and dehydrated

Light, long-lasting and useful for travel or as backup food. Check that it says "complete" on the label, because many are sold as treats or toppers.

Reading the label

• Look for a "complete" feed statement for your cat's life stage. In the EU, reputable brands follow FEDIAF guidelines.
• The ingredient list is a weak guide to quality. WSAVA advises asking the maker who formulates the recipe (a qualified nutritionist), whether the finished food has been tested, and whether the company can answer your questions.
• Vague terms such as "meat" or "poultry" tell you little about what's inside.
• For adult cats, the AAFCO minimum is 26 percent protein and 9 percent fat on a dry matter basis.
• Terms like "premium" or "natural" have no nutritional meaning.

Life stages

Kittens (up to 1 year). Kitten food has more protein, fat, calories and calcium for growth. Feed 3 to 4 small meals a day. See our veterinary services for kitten check-ups.

Adult cats (1 to 6 years). Aim for steady weight. Two meals a day work well, and indoor cats need fewer calories than active ones. As a rough guide, a 4 kg neutered adult needs around 200 to 250 kcal a day, but your cat's body condition matters more than the feeding chart.

Mature and senior cats (from 7 years). The AAHA and AAFP count 7 to 10 years as mature and over 10 as senior. Older cats should have their weight checked regularly, because both weight gain and weight loss can signal illness. Yearly blood tests help the vet judge kidney health.

Special diets

A vet should decide when a cat needs a therapeutic diet. The usual reasons are:

• Urinary problems, such as struvite or oxalate crystals or stones
• Kidney disease, which calls for reduced phosphorus
• Food allergy. The most commonly reported triggers are beef, fish, dairy and chicken. Wheat and corn are less often involved. The only reliable test is an elimination diet trial led by your vet
• Digestive disease
• Overweight

Signs of a food allergy are itching, hair loss, over-grooming, chronic ear infections and vomiting or diarrhoea.

Grain-free

Grain-free isn't better for most cats. Cats need few carbohydrates, and grain-free foods often swap grain for potato or peas. The US FDA's investigation into grain-free diets and heart disease (DCM) was driven mostly by reports in dogs, and it has not established a cause. Choose grain-free only if a vet has diagnosed a grain allergy, which is rare.

How to feed

• Weight. Weigh portions instead of eyeballing them. You should feel your cat's ribs under a thin layer of fat.
• Meals. Two or three scheduled meals suit most cats. Free feeding makes overeating easy, and fixed meals let you notice a change in appetite quickly.
• Treats. Keep them under 10 percent of daily calories.
• Several cats. Use separate bowls or feeding spots so no cat guards food or eats another's share. A feeder that opens with a microchip helps when one cat needs a special diet.

Changing food

Switch over 7 to 10 days:

1. Days 1 to 3: 75 percent old food, 25 percent new
2. Days 4 to 6: half and half
3. Days 7 to 9: 25 percent old, 75 percent new
4. Day 10: all new food

If your cat refuses the new food, slow down. Never leave a cat without eating for more than a day or two, because it can lead to serious liver problems. Call your vet if that happens.

Water

Cats often drink little. Put out fresh water in several spots, away from the litter tray, and try a fountain if your cat likes running water. Wet food adds a lot of water to the day.

Treats, supplements and dangerous foods

• Onions, garlic, chocolate and grapes are toxic to cats. Don't feed table scraps.
• A complete food doesn't need supplements. Ask your vet before adding probiotics, omega-3 or anything else.

Signs the food suits your cat

A glossy coat, healthy skin without constant itching, good muscle and an ideal weight, normal energy and appetite, firm stools, and clear eyes and clean ears.

When to see a vet

Book an appointment if your cat:

• Changes appetite suddenly
• Loses or gains weight without explanation
• Vomits or has diarrhoea for more than a day or two
• May have a food allergy
• Needs a diet for a medical condition

We advise on diet during a veterinary appointment. Our clinic is open Monday, Thursday and Friday 10:00 to 16:00, and Tuesday and Wednesday 09:00 to 17:00. Outside those hours, contact an emergency vet clinic if your cat is seriously unwell.