What to Do When Your Cat Won’t Eat

Medically Reviewed by Amy Flowers, DVM on November 07, 2021
5 min read

People joke about cats and their finicky eating habits, but it’s actually a serious issue if your cat won’t eat.

Although a refusal to eat is a cause for concern for all pets, it can be more dangerous for cats.

When animals don’t eat enough, they must rely on their fat reserves for energy. Before stored fat can be used for fuel, it must be processed by the liver. This step requires adequate supplies of protein.

With rapid weight loss in a cat that stops eating, protein supplies are soon exhausted and the liver becomes overwhelmed by all the fat. This results in a dangerous condition known as hepatic lipidosis, which can lead to liver failure.

A loss of appetite often means your cat is ill, so you should consult your veterinarian as soon as you notice a change in eating habits. The more quickly you respond to the problem, the more able you'll be to do something that will help.

Illness. Loss of appetite is one of the key clues that something is wrong. So be sure to pay attention if your cat suddenly stops eating. A number of different conditions may be responsible, including infections, kidney failure, pancreatitis, intestinal problems, and cancer. But it isn’t always serious -- something as simple as a toothache can make your cat stop eating.

Recent vaccination. Did you notice your cat’s loss of appetite shortly after you took it to the vet for routine vaccinations? If so, the reason your cat won’t eat may be a bad reaction to the shots. Although vaccines have been lifesavers for millions of animals, they do cause side effects in some. Loss of appetite is among the more common of these side effects, which are usually temporary and mild.

Travel and unfamiliar surroundings. Like many people, many cats are creatures of habit. So a change in routine can result in a loss of appetite. And some animals get motion sickness when traveling by car or plane, which can lead to nausea and a refusal to eat.

Finickiness or psychological issues. If your veterinarian has found that your cat is not physically sick, then anxiety or depression could be the reason your cat won’t eat. Changes in their routine or in the household can be disturbing to sensitive cats, and sometimes new people or pets – or the disappearance of another pet – can affect a cat’s emotional well-being. Or your cat could just be a finicky eater. Keep in mind that cats, in general, take a long time to adjust to new types of food, so a recent change in diet could be the culprit.

Other situations that may upset your cat include excessive noise, other animals in their feeding area, dirty food dishes, or their food dish being too close to their litter box

Unexpected weight loss in a cat is usually a sign of a health issue. If it happens gradually, you may not notice right away, especially if your cat has long hair. It's a good idea to weigh your cat and do a condition check regularly and let your vet know right away if you notice any changes. There are a number of reasons why your cat could suddenly lose weight: 

Diabetes. This disease, which may be caused by a failure to produce the hormone insulin or an impaired ability to respond to it, commonly causes weight loss in cats, often with a change in appetite. Cats with diabetes may also drink excessive amounts of water, urinate more than usual, act sluggish, get urinary tract infections, and have sweetly scented breath.

Feline infectious peritonitis. This virus, which most commonly occurs in cats raised in catteries, is known to cause wasting. Cats with FIP will seem sick, often with a fever that doesn’t respond to antibiotics.

Gastrointestinal problems. There are a variety of conditions in the gastrointestinal tract that may cause cat weight loss. When this is the case, other symptoms may include diarrhea, lack of appetite, and vomiting. Common GI problems that produce weight loss in cats include inflammatory bowel disease, food allergies, and certain infections.

Intestinal parasites. Also known as worms, intestinal parasites may be the cause of your cat’s unintentional weight loss. Although symptoms are not always present, these parasites also may cause diarrhea, bloating, vomiting, and trouble breathing.

Organ failure. Many elderly cats lose weight, and it can be hard to know the precise cause of the problem, especially because metabolism changes with age. Conditions such as kidney disease become more common as cats get older. Your veterinarian can identify these problems with simple blood and urine tests.

Hyperthyroidism. Your cat may have a good appetite; in fact, they may be eating more than usual but still losing weight. Hyperthyroidism results from a benign hormone-producing tumor on the thyroid gland that raises thyroid hormone levels. In addition to weight loss, hyperthyroidism may cause increased drinking and urination, increased activity, vomiting, diarrhea, and muscle wasting. In later stages, it may even lead to heart problems or death. Older cats also are particularly prone to this condition.

Whether your cat is sick, anxious, or just plain picky, remember that a complete refusal of food can have devastating consequences. So, even if you’re trying to make your cat eat a doctor-prescribed diet, never starve your cat into eating a certain type of food.

If illness is the reason your cat won’t eat, work with your veterinarian to design the best plan for you and your pet. This may include a change in food type or consistency; some cats may be enticed to eat by offering canned foods when they are unwell. In more extreme cases, veterinarians may prescribe medicines that act as appetite stimulants or recommend syringe-feeding your cat a liquid diet. Or the vet may recommend placement of a feeding tube to ensure adequate nutrition.

When illness is not the culprit, there are things you can try to encourage your cat to eat.

You may have found that certain foods, such as liver or canned tuna, can stimulate a cat's appetite. Remember to only offer these foods in small amounts. Large quantities may harm your pet by causing deficiencies or an overabundance of certain vitamins.

Instead of relying on people food, try encouraging your cat to eat commercial canned food. You may find that heating the food or mixing in fish oil, broth (make sure it does not contain onions, which are toxic to cats), or cooked egg could entice your picky cat to eat. If your cat still won’t eat, take the food away and provide fresh food later in the day. If the food is left to harden and become stale, your cat may learn to avoid it in the future. 

If your cat has been eating human food exclusively, be sure to transition your pet over several weeks by mixing together your pet’s favorite people food with cat food. Over time, you should be able to change the ratio until your pet is eating only cat food.

Many experts recommend rotating your cat’s diet among different brands two to four times a year by using a similar technique. This practice may help reduce finickiness and also lessen food allergies and intestinal problems.