Wet food or dry food: what should my cat eat?

Cats are obligate carnivores. In the wild they eat prey high in protein, moderate in fat and very low in carbohydrate, so a cat cannot be a vegetarian. A cat also cannot make enough taurine, arginine, vitamin A (from animal tissue, not from plants), arachidonic acid and niacin itself. These must come from animal tissue in its food.

Taurine matters for the eyes, the heart muscle, growth and reproduction. It occurs in meat, fish, shellfish, poultry and eggs, and plants have none. A cat stores little of it and needs it every day. Too little slowly damages the retina (which can end in blindness) and weakens the heart muscle. Signs can take months to show. The heart problem can reverse if caught early; retina damage usually cannot.

Cats have a short gut, digest starch poorly and do not need carbohydrate to keep their blood sugar normal. They also need more protein than most mammals, and more than dogs. A cat needs a complete diet in the right amounts for its life stage: kitten, pregnant or nursing, neutered or senior. Since the late 1980s food made for cats has had taurine added, so a shortage is rare in cats that eat a commercial complete food.

Both wet and dry commercial food can be complete, so a cat can live fully on either. The choice is largely about your cat's liking and your situation, as long as the food is complete. The type matters less than the food itself: quality and formulation vary enormously within both wet and dry food.

Water content is the main difference. Dry food holds about 6 to 10 percent water (some sources say up to 14). Wet food in cans, pouches or trays holds about 75 percent or more. Semi-moist food sits in between at about 35 percent. Dry food is much more energy dense, so a correct portion looks small. Wet food usually has fewer calories for the same volume and fills a cat more, which can help with weight control, though this depends on the product.

Dry food is usually the cheaper option, is easy to portion and store, keeps well, can be left out for grazing and can go in puzzle feeders. The downsides: the cat has to drink well, and depending on the product the protein can be lower in quality or less digestible. Wet food adds water, is softer for older cats and cats with dental problems, is tasty for many fussy eaters and is low in starch. It costs more and spoils faster once opened.

Many guides suggest feeding both: water and taste from wet food, convenience from dry. Dry food alone is not unsafe: vet bodies call it safe as long as the cat gets the water it needs, and many cats on mainly dry food live long, healthy lives. Offering wet and dry food in two separate bowls shows what your cat prefers and whether it will eat both. Offer different textures from kittenhood: cats that ate only one dry food for years often refuse wet food later.

Cats have a low thirst drive. On a dry diet they drink more, but not enough to make up for the water they would get from wet food or prey (about 70 to 75 percent water). In a small study of six cats, from a pet food company's research centre, the same food with more water led to more total water intake and more dilute urine. It tested one food at different moisture levels, not wet against dry products.

Earlier studies linked dry food to a higher risk of lower urinary tract disease in susceptible cats, and wet food to fewer repeat bladder stones and cystitis. Vets may advise wet food only for cats with urinary or kidney problems; which food is right then is a vet's decision. It is not proven that dry food on its own causes kidney disease, bladder stones, obesity or diabetes.

To raise water intake: feed some wet food, put water bowls in several rooms away from the food and the litter box, try a wide, shallow ceramic or glass bowl, or use a drinking fountain. Change the water at least once a day. If your cat suddenly drinks more or less than usual, that can signal a medical problem. Tell your vet.

A few consumer guides say dry food is a bit better for teeth. None of them cite a study, and the vet and university sources we read do not show that kibble cleans teeth. Dental claims on packs of kibble and treats are often marketing. Raw bones are not a safe answer either: they can break teeth and cause blockages, and no difference in gum disease was found between pets fed raw bones and pets fed conventionally.

Wet food is easier to chew for cats with dental problems and for older cats. A cat that eats on one side of the mouth, makes a grinding noise or drops food may have pain in the mouth and should see a vet. Ask your vet how to look after your cat's teeth.

Complete food has all the nutrients in the right balance, so nothing else is needed. Complementary food, such as treats, is meant to be combined with other foods and is not a full diet. Choose a food labelled complete. In Europe the label must say whether a food is complete or complementary, and for which species and life stage. The FEDIAF guidelines, written by the European pet food industry and reviewed by independent veterinary nutritionists, are the reference manufacturers follow. They are an industry document, not law. Outside Europe an adequacy statement, such as the AAFCO one, does the same job.

Check that the pack says the food is made for cats and for your cat's life stage (kitten, adult, or all life stages). Foods marked for 'intermittent or supplemental use only' are not complete, apart from vet-prescribed diets for a specific purpose. A complete food needs no extra vitamins or minerals unless your vet advises it: supplements can unbalance the diet, and some nutrients are toxic in high amounts. Canned food needs more added taurine than dry food, because heating loses some.

Some medical conditions are eased by a prescription diet, which a vet chooses. Do not give such a diet to a healthy cat and do not switch it without the vet.

A label gives too little information to judge nutrient levels or ingredient quality. Ingredient names do not show digestibility or quality; what counts is a finished food that was formulated and tested. You can ask the maker. Words like premium, natural, holistic or human grade have no legal definition and do not show that a food is complete or better. Price is no guarantee either: a consumer test found the cheapest products scored lower, but affordable ones could score well.

Cereals are not just fillers: properly cooked grains give energy, fatty acids and fibre in a complete diet. A by-product is an ingredient made alongside another, and edible offal such as liver is nutrient rich. Meat named on the pack is often a small share of the product. Ingredients are listed by weight, so meat, meat by-products or seafood among the first few suggests enough animal protein. A higher protein percentage is not better in itself: almost all complete foods already exceed the minimum.

Grain-free does not mean low-carbohydrate: some grain-free foods contain more carbohydrate than foods with grain. A review looked at a possible link between legume-based grain-free diets and heart disease in cats (14 cases); the link is not proven. A claim such as 'with vitamin E' does not mean extra vitamin was added.

The feeding guide on the pack is a starting point, based on an average cat of a given weight. Individual cats can differ by up to 50 percent and manufacturers tend to overestimate, so adjust the amount to your cat's body condition. What a cat needs depends on its age, activity, neutering and ideal weight. For an overweight cat, work from the ideal weight, not today's weight. To answer 'how many grams' or 'how many pouches', look at the kcal per 100 g or per pouch or can on your food, and at the daily guide for your cat's weight on the pack. The same weight of different foods holds very different amounts of energy.

Measure food rather than judging by eye. Dry food is energy dense, so weighing it is more exact than a scoop. Weigh your cat and adjust the amount about every 2 weeks at first, until it has reached and keeps an ideal weight. As a general figure only, one consumer test says a healthy adult cat needs about 200 to 300 kcal a day. This is not an amount for your cat; your vet can work out a figure for it.

Cats are grazers. In the wild they eat roughly 10 to 15 small prey a day, and pet cats allowed to choose often eat many small meals, between 8 and 16 a day. Little and often suits them. For an adult cat, charities suggest fresh wet food at least twice a day and dry food at least once or left out for grazing, or the day's food split into five or more portions with timed or puzzle feeders. Leaving food out only suits a cat that regulates its own intake. It should not be used for a cat that is prone to overweight; give measured meals instead. Wet food must not sit out for hours.

Kittens have small stomachs and need smaller meals more often of an energy-dense kitten food (see the schedule below and our kitten page). Pregnant and nursing cats need much more energy; the vet can advise. A nursing cat may eat double or triple her usual amount. In a home with several cats, give each cat its own bowl in a different spot. A microchip-activated feeder or a separate room can keep an overweight cat from eating the others' food. Put the bowl in a quiet place away from the litter tray, windows, cat flaps and busy areas. Wide, shallow glass or ceramic bowls suit most cats. Noise, other animals, dirty bowls and a nearby litter box can stop a cat eating. Puzzle feeders, timed feeders and scattered dry food let a cat hunt for its meals, which adds exercise and stimulation.

Obesity is the most common nutrition-related problem in cats. It raises the risk of diabetes, arthritis, bladder problems, heart disease and anaesthetic complications, and can shorten life. Most overweight cats simply eat more than they use, and indoor life with little play makes this easier. A medical cause is rare, but illness that slows a cat down can add weight, so ask the vet. Cats under about two years rarely gain weight. Between two and ten years they use less energy and are at more risk. Cats over about 12 are more likely to be underweight.

Body shape is a better guide than the scales, because ideal weight differs between breeds while a healthy shape is the same. Look from the side and from above, and feel the ribs, spine, hips and tummy. A healthy cat has ribs you can feel under a light touch, a visible waist from above and a slightly tucked belly. An overweight cat has no clear waist and hard-to-feel ribs; an obese cat's ribs cannot be felt. Two scales are in use, so always say which one: on the 5-point scale 3 is ideal; on the 9-point WSAVA chart 4 to 5 is ideal (some recent work suggests 5 to 6), and a 3 on the 9-point scale means thin. Overweight means more than about 15 percent above ideal weight and obese more than about 30 percent.

Long-haired cats and large breeds are harder to judge by eye, and photo scoring is less reliable between 'ideal' and 'overweight'. Ask your vet to score your cat in person and show you how. After neutering, energy needs fall (estimates run from about 10 to 30 percent) while appetite often rises, so cats gain weight if the amount is not adjusted. There is no law or guideline for 'neutered' food, and such food is rarely much lower in calories. Wet food does not make cats fat by itself: because it is usually less energy dense and more filling, it can help keep weight steady, but treats, scraps and generous portions still add up.

Weigh your cat regularly and write the result down, since weight changes are hard to see on a cat you meet every day. Check body shape every few weeks. A cat that needs to lose weight should lose it gradually. Never starve a cat or put it on a crash diet: even a short time without food can harm it, and a very overweight cat can take up to a year to reach a healthy shape. A thin cat, or one losing weight without a clear reason, should see a vet to rule out illness such as an overactive thyroid before the diet is changed.

Wet food usually costs more than dry food per serving. One source puts wet at about twice the price of dry on average, but prices vary enormously by product. A high price does not mean a better food. Unopened dry food keeps about a year and about 3 months once opened. Keep it in its original bag, airtight, in a cool dry place, and check the expiry date. Decanting can shorten shelf life and makes it harder to trace a batch. Opened wet food goes in the fridge and should be used within 2 to 3 days. Do not leave wet food out for hours; change it at least twice a day. Let chilled food warm up to room temperature before serving, as cats prefer it near body temperature.

Change food gradually. Mix a little new food into the old and increase it over a week or more, longer for a sensitive stomach. WSAVA gives an example of 75/25, 50/50, 25/75 and then all new over at least 3 days; other sources say 1 to 2 weeks. Go back to the old food if the cat refuses it or becomes unwell. Cats do not need variety for their nutrition, and frequent changes can upset the stomach. Some variety of texture and flavour when young helps a cat stay open to other foods.

A sudden change of food or portion can lead a cat to refuse food for days. In an overweight cat this can lead to a liver syndrome, so call the vet if your cat refuses food for several days. Do not change the diet yourself when you suspect a problem: it can make things worse. The vet can draw up a feeding plan. A cat on a prescription diet should not change food without the vet.

Treats are extra calories and are not a complete diet. Keep them to about 10 percent of the day's energy, count them in the day's total and cut the meals to match. Human food adds calories fast: a small cube of cheese for a cat counts like nine cubes for a person. Many cats value play and attention as much as food, so a puzzle feeder or a new toy can replace some treats. A little well-cooked, plain chicken or fish now and then is fine. Tuna is an occasional treat only. Specially made cat milk is high in calories, an occasional treat and never a replacement for water. Dental and calming claims on treats are often marketing.

Raw food: vet bodies and universities advise against raw feeding. Raw food can carry Salmonella, Listeria, E. coli and parasites such as Toxoplasma, which can make the cat and the people at home ill. A cat can carry bacteria without showing signs and shed them in saliva or faeces. In a 2011-2012 screening nearly 25 percent of commercial raw pet food samples carried harmful bacteria. Raw food producers cannot heat-treat their food, and freeze-dried raw treats can still carry live Salmonella. Raw feeding is riskiest in homes with young children, older people, pregnant people or anyone with a weak immune system. The claimed benefits, such as a shinier coat, cleaner teeth or stronger immunity, have no scientific evidence. 'Natural' is not the same as healthy. For healthy adult cats vets advise a complete and balanced diet that is cooked and tested for harmful bacteria. If you still feed raw, tell your vet and keep to hygiene: wash hands and surfaces, keep raw food frozen and thaw it in the fridge, and do not let the cat lick your face.

Raw fish has a further risk: an enzyme in some raw fish, thiaminase, breaks down thiamine (vitamin B1). A cat fed mainly raw fish can develop deficiency, with poor appetite and vomiting, then vision loss, unsteady walking, tremors and seizures. A fish-only diet also lacks other nutrients.

Home-cooked diets are very hard to balance. A review by a veterinary school of 114 recipes from books and the internet found that none of the 94 that could be analysed met all essential nutrients for adult cats. Most lacked three or more, and about 7 percent included ingredients toxic to cats, such as garlic, onions or leeks. Recipes written by vets had fewer shortfalls but still lacked nutrients. Cooking changes the food: boiling loses more taurine than baking or frying, and heating destroys other nutrients. If you do cook for your cat, use a recipe from a board-certified veterinary nutritionist (not a generic one from the internet) and have your cat checked regularly, including blood tests. Your vet can refer you. Commercial complete food is not 'dangerous': the risk is in unchecked homemade recipes.

Vegetarian and vegan food: WSAVA says cats should not be fed vegetarian or vegan diets, and other vet bodies advise against them. This page does not recommend them either. Plants contain no taurine, so a plant-only diet depends on synthetic taurine, arginine, vitamin A, B12 and arachidonic acid. Plant proteins also acidify urine less, which may favour struvite crystals, so urine needs monitoring. Tests have been poor: all 3 canned vegetarian diets for cats in a 2015 analysis were too low in taurine, and only 8 of 24 vegetarian diets met all label rules. A 2023 survey of 1,369 owners found no clear harm except slightly more kidney disease, but the data came from owner reports and cats hide illness, so it cannot show long-term safety. Deficiencies take a long time to appear. Weight loss, a poor coat, lethargy or digestive problems can be early signs. Do not switch a cat to a meat-free diet without a vet's advice and monitoring. Prescription non-meat diets exist for specific medical needs and are risky for a healthy cat.

Not as its food. Dogs can make taurine from other amino acids, cats cannot, and dog food does not contain enough taurine for a cat. The balance of nutrients does not suit a cat's digestive system either. In one set of tests, some dog foods contained remarkably low levels of taurine, methionine and cysteine. Taurine deficiency builds up slowly, over months, and shows up as damage to the retina and the heart muscle, so a cat can look fine until the problem is advanced.

Occasionally eating a few mouthfuls from the dog's bowl is not a serious problem, according to a nutrition site; the risk is a cat that eats dog food as its main food. More generally, food made for another species should be avoided, because complete cat food is formulated for a cat's needs. If it happens often, tell your vet.

Onion, onion powder, garlic, chives and leek are poisonous to cats and other pets. Chocolate (theobromine), coffee and tea (caffeine), grapes and raisins, macadamia nuts, xylitol (in sugar-free gum, candy and some peanut butters), alcohol, yeast dough and salty or mouldy food are on lists of foods that harm pets. Many lists cover pets in general, not cats only, so do not experiment. If your cat may have eaten something toxic, contact a vet immediately.

Milk and dairy: most adult cats lose the ability to digest lactose after weaning, and milk causes diarrhoea or vomiting. Cats need fresh water, not milk. Liver in large amounts or too often gives too much vitamin A, which can cause serious illness: do not feed only liver. Canned fish made for people: some cats that ate it developed potentially serious neurological disorders, and a fish-only diet lacks other nutrients. Bones, raw or cooked, can splinter or get stuck in the throat or gut. Jerky and dried sweet potato treats have been linked to kidney disease in several parts of the world and are discouraged. Salty, spiced or fatty human food, such as spiced sausage and salami, is harmful or fattening. Table scraps unbalance the diet, make cats overweight and can make a cat refuse its own food.

If a cat that normally eats well suddenly stops, or has not eaten for 24 hours, see the vet. Cats that go without food for a few days can develop a liver condition that can be fatal. Not being hungry suggests a medical problem, while disliking a food is a preference. Ask the vet to rule out illness before you offer more foods. Cats eat largely with their nose, so a blocked nose can stop them eating. A cat that refuses to eat and is losing weight needs a vet check. Do not force-feed a cat: it can cause food aversion and aspiration pneumonia.

Fussy eating can come from stress or illness. Warmed, strong-smelling food, a ceramic bowl or hand-feeding sometimes helps. A cat that eats wet food but not dry is not a problem if the wet food is complete. A cat that suddenly drops one type or eats on one side of the mouth may be in pain.

WSAVA asks vets to make a nutritional assessment at every visit (the 'fifth vital sign') and to give a diet recommendation for each patient. Owners meet many nutrition myths that can harm if acted on. Some diseases can be eased by diet, but this should be done under veterinary guidance: kidney or liver diets, for example, are chosen by a vet and can harm a cat that does not need them. A healthy cat on a good complete food does not need taurine supplements. Vets use them for cats with some health problems, and quality varies between makers, so ask your vet which to use.

Food allergy is a less common cause of itching than fleas, environment and atopy. If a food problem is suspected, the vet can test for intolerance and suggest complete adapted foods. Warning signs of a food problem include stools that are too thin or too firm, a poor coat (a possible vitamin or mineral shortage), and itching or stomach complaints. A vet decides the cause.