A Trusted Friend in a Complicated World

14 Cat Health Symptoms You Should Never Ignore

Book an appointment with the vet if you notice any of these cat symptoms and abnormal behaviors

1 / 14
Closeup of Hypnotic Cat Eyes

Eye problems

“If you see anything abnormal with your cat’s eye, that is enough to warrant a visit to the vet,” says Evan Antin, DVM, a veterinarian with Conejo Valley Veterinary Hospital. Cat symptoms that affect the eye should be especially watched. Check for blood, yellow or green discharge, excess tears, or a hazy, gray color change—any of those vision symptoms should be taken seriously, he says. Find out why you should never let your cat sleep in your bed.

2 / 14
Cute cat eating food in a green bowl on wood table and white background.
Pitipat Usanakornkul/Shutterstock

Loss of appetite

Just as humans don’t feel like eating when they’re sick, animals lose their appetites too. Don’t freak out if your cat turns its nose at one meal, but going a full day without eating could be a sign of a slew of feline health issues, from stomachaches to respiratory problems to dental issues. Ashley Rossman, DVM, a veterinarian with Glen Oak Dog & Cat Hospital, says that a lack of eating is one of the symptoms owners are most likely to blow off for too long. “Don’t wait five days—after the first 24 to 36 hours, bring the cat in,” she says. “It’s not good for the cat to not eat. They could get fatty liver disease.” The sooner you visit the vet, the sooner your cat can get healthy.

3 / 14
Meowing cat demanding eating sitting near empty bowl


You recognize the sound of your cat’s normal noises, but listen up if its mews have turned to yowls. “If you have a cat that’s really uncomfortable and yowling nonstop, that should tell you something’s going on,” says Dr. Antin. “That cat is in real pain.” Bring it to the vet to get to the bottom of the issue.

4 / 14
Beautiful bengal cat playing in the house
Ingus Kruklitis/Shutterstock

Sudden energy from older cats

No, your playful new kitten probably isn’t warning you of any health problems. But if your lazy aging cat is suddenly bouncing off the walls, you might want to ask a vet for some blood work. “If they’re hyperactive and losing weight and sometimes vomiting more, that would be a common thing to see with hyperthyroidism,” says Dr. Antin. This cat diet will keep your pet in-balance and healthy.

5 / 14
Cat looking at camera while next to litterbox
Jennifer McCallum/Shutterstock

Blood in the litter box

If you spot blood in your cat’s litter box, that’s one of the cat symptoms that should get you to call the vet for an appointment, says Dr. Rossman. Your pet might be dealing with anything from a UTI to bladder cancer, so getting a diagnosis is the first step to getting treatment.

6 / 14
Tabby and white short hair cat with mouth open and lick its lips
Lee waranyu/Shutterstock

Excess vomiting

Dealing with hairballs is just part of being a cat owner, but don’t shrug your shoulders at a kitty that’s constantly vomiting. “If they’re vomiting more than two or three times a week, they need to seek professional help,” says Dr. Rossman. This is one of a few cat symptoms that might mean your cat has food poisoning, pancreatitis, or stress, and a vet can lead you to a diagnosis.

7 / 14
cat in litter box.

Extra clumps in the litter box

Take note if your cat’s water dish is emptying faster than usual; it could be the first clue that your cat is having kidney problems, says Dr. Antin. “Felines are carnivores and have very high-protein diets,” he says. “Protein is very demanding on the kidneys.” So if your cat is dealing with a UTI or chronic kidney dysfunction, it might need to pee more, then lap up extra water to make up for the dehydration. Stop doing these 13 things your cat hates.

8 / 14
The cat hides in the box, white background, close-up
Elena Vesnina/Shutterstock

More hiding

Cats can be notoriously skittish, so you might not think twice if your kitty keeps disappearing under the bed. But if your cat is hiding more than usual, it could be one of the cat symptoms or signs that your pet is in pain or isn’t feeling well. “They could feel more secure in their hiding spot than out in the open,” says Dr. Rossman. “It’s their safety net.” It’s easy to spot abnormal shyness in a more social cat, but the behavior change is harder to spot in a timid kitty, Dr. Antin points out. If your cat is hiding in different places or for longer periods and is displaying other symptoms, take it to the vet, he says. Extra hiding is particularly concerning in older cats, which could be developing cancer or metabolic issues, he says. Check out these other 17 things your cat wishes you knew.

9 / 14
Blue eyed cat
Esin Deniz/Shutterstock


Cognitive decline in your pet could cause a host of cat symptoms, from meowing more to seeming disoriented. Yes, some cats will respond to treatment for senility, but that’s not the only reason to check with a vet. “There are other things that can cause that odd behavior that are not actually senility,” says Dr. Antin. “This other stuff might be treatable.” For instance, your cat might have eaten something toxic or be dealing with kidney disease, but you’ll need to rule those out before trying any medications for cognitive decline. Make sure you know these 11 subtle signs your cat is depressed.

10 / 14
Tabby cat in a litter box

Missing the litter box

A cat that’s stopped using its litter box might be sending a message by marking its territory, but you’ll still want to take it to the vet. What you assume is a behavior problem might actually be a medical issue, such as bladder cancer or a kidney stone, says Dr. Rossman. “It’s always good to rule out the medical things first because those are easier to fix than the behavioral ones,” she says.

11 / 14
Scottish Fold. Portrait of a gray adult cat. Selective focus
Nataliia Budianska/Shutterstock


“Most neurologic things a human would have, a pet can have as well,” says Dr. Rossman. Especially if your cat isn’t an epileptic, you should be concerned if you see it roll back its eyes, lose consciousness, or lose control of its bowels. Put it in a padded area without getting your hands near its mouth, then call the vet ASAP, she says. Avoid these other 12 dangerous mistakes cat owners should never make.

12 / 14
Cat on door step
Pongsak A/Shutterstock


If your cat is suddenly and excessively drooling, that could be a sign of any number of health problems. Some issues that cause cat drool are dental disease, kidney failure, and cancer, among other others, according to Pet Health Network.

13 / 14
White cat with yellow eyes sitting near an empty bowl on a blue wooden background
Evgeniya Tomashevskaya/Shutterstock


A cat that has trouble going to the bathroom is likely dehydrated. Pet Health Network reports, however, that in some cases constipation in cats could stretch the colon, requiring surgery. Look out for these 15 signs your cat is secretly mad at you.

14 / 14
portrait of a skinny white and red cat in Africa, outdoors with natural sunlight

Sudden weight loss

Beware of any cat symptoms that are a big, sudden change from the norm. For example, cats that suddenly drop a few pounds could have any of numerous health issues, including cancer, heart disease, kidney or liver problems, or diabetes, according to WebMD. Next, check out the 11 warning signs of cancer in cats that every owner should know.

Marissa Laliberte
Marissa Laliberte-Simonian is a London-based associate editor with the global promotions team at WebMD’s Medscape.com and was previously a staff writer for Reader's Digest. Her work has also appeared in Business Insider, Parents magazine, CreakyJoints, and the Baltimore Sun. You can find her on Instagram @marissasimonian.