How to Tell if Your Cat Is Sick

By: Shanna Freeman & Dr. H. Ellen Whiteley  | 
sick cat
Is your cat just sleeping a lot, or is she really sick? NurPhoto/Getty Images

Unfortunately, cats are notorious for trying to hide their illnesses. All too often, pet parents don't realize that something is wrong with their feline friend's health until it's serious. Obviously, a cat can't explain to you what’s making him feel ill — it’s hard for humans to decipher those meows and purrs to get an idea of what's going on inside. But in many ways you might otherwise overlook, your cat is making clear statements about his health.

While there's no substitute for the advice of your veterinarian (and you shouldn't hesitate to call a vet with your concerns), you can gauge your cat's health by paying close attention to his behavior and appearance. This includes making a general once-over part of your routine, perhaps by working it into grooming or another regular activity. That way you can find out what's normal for your cat and potentially catch minor problems or illnesses before they become major ones. There are also warning signs that might tell you there's something that warrants further investigation.


If you decide that a visit to the vet is in order, you can provide crucial information that will help your vet make a diagnosis. Often a cat will "act funny" at home, but he'll be so nervous at the vet's office that he won't do anything. The more accurate your report, the better your vet can determine what's going on. And since describing your cat's condition as "funny" or "sick" is a little too vague, you need to be specific.

In this article, you'll learn how to get a sense of your cat's health, how to recognize important indicators of potential problems and the best ways to share your findings with your vet. Read on to find out how what your cat eats (and how often he uses the litter box) can shed light on his health.

Appetite and Elimination Are Indicators of Feline Health

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Changes in your cat's eating habits can be a sign of illness. Marka/Getty Images

Keeping a close eye on what goes into and out of your cat's body can be a good indicator of its health. You may notice that your cat isn't eating as much as before, but you also need to know the context. For example, does he just seem uninterested in food entirely? Or does he come running as usual for his food but then eats little (if any) of it? In the first case, it would be completely correct to say your cat has no appetite. In the second, he has an appetite but something is making him feel like he can't eat very much.

A cat who hasn't been eating well may also not be drinking enough and could become dehydrated. To check whether your cat is getting enough to drink, gently grasp the skin between his shoulder blades, pull up slightly and open your fingers to let go. If the skin snaps back into place immediately, your cat is well hydrated. If not, your cat could be dehydrated and may need to get fluids at your veterinarian's office to prevent serious harm. On the other hand, if your cat is suddenly drinking more water than usual, that could also be a sign of a problem, such as a metabolic disorder.


It's usually not polite to talk about elimination, but the litter box is important in understanding the health of your cat. Are his stools well formed, soft or loose? Is there any trace of blood in his urine or feces? Is there mucus in the stool? Even things like a change in color or odor can be important.

Of course, eating and elimination are two sides of the same coin (or two ends of the same digestive system, to be more accurate), so pay attention to how they go together. For example, if your cat has a ravenous appetite but doesn't seem to put on any weight (or actually seems thinner), that should alert you to a possible problem. If you've noticed big changes in your cat's appetite or elimination habits, take him to the vet to determine the cause of the problem.

Now that we've gotten past the messy part, read on to find out why simply petting your cat can reveal how he's feeling.

Checking Your Cat's Coat and Body

A healthy, well-groomed cat has a soft, clean, slightly lustrous coat. A cat whose fur is dull, dry, oily or unkempt may just need you to step up his grooming routine, or he may be under the weather. Even with regular grooming by humans, a cat needs to do some of his own grooming to keep his coat looking good. Cats are usually pretty diligent about their personal hygiene, so a cat who's not keeping up his appearance may not be feeling well.

On the other hand, a cat who's grooming himself raw is also telling you something. Excessive grooming can be a sign of stress, a skin problem or a reaction to fleas. Look for "hot spots" — patches where your cat licks so much that the fur is gone and the skin is red or raw. This condition, called moist acute dermatitis, can be a sign of many different kinds of conditions. These may include an insect bite, a flea infestation or an allergy.


Of course, not all hair loss is from grooming. Take note of any bald patches or areas where the hair is thin or sparse. Most of your cat's body should be covered with a coat of hair thick enough to hide the skin underneath. (About the only place where it's normal for the fur to be thinned out is the area between your cat's eyes and ears.) Whatever the case, your vet's advice will help put your cat back on the path to a healthy coat.

While you're checking out your cat's coat, you should also do a quick assessment of his weight. Run your hands over the cat's sides — in a cat at a healthy weight, you should just be able to feel ribs. If the ribs are very prominent, your cat could be underweight. If you're having trouble finding ribs, then he or she could be overweight. Just as in people, an overweight or obese cat can develop a host of health problems. Discuss any concerns about your cat's weight with your vet.

Do you brush your cat's teeth? If not, the next section might make you think about giving it a try.

Looking Inside Your Cat's Mouth

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Examining your cat's mouth can tell you a lot about his health. Auscape/Getty Images

Every cat owner should know how to open a reluctant cat's mouth because the gums and teeth are good indicators of his or her health. The best way is to grasp the top of your cat's head with your thumb on one side and your fingers on the other. Your cat is not likely to think this is great, so be as kind as you can. Tip your cat's head back so his nose points upward. Now, using your other hand, put one finger where the front teeth meet and push down gently with steady pressure on the lower jaw. As your cat's mouth opens, you'll have a few seconds to get a good look inside.

The color of the skin in your cat's mouth and on his gums tells an important story. A healthy cat usually has a tinge of pink. Stark white could be a sign of anemia. A yellowish cast is often a sign of liver trouble. A bluish tint may mean your cat isn't taking in enough oxygen, usually a result of a respiratory problem or poisoning. A word of warning, though: It's not unusual for a cat's gums — and even the roof of his mouth — to take on some of his coat color, especially as he gets older. For some reason, orange cats are also prone to developing harmless "freckles" (known as lentigo simplex) on their noses, lips, gums and inside their mouths. Black gums on a black cat aren't anything to worry about, but any gum changes should be reported to your veterinarian right away.


While you're looking around in there, you should also give your cat's teeth a checkup because tooth problems can lead to something more serious. Tartar buildup, for example, does more than cause bad breath. When tartar builds up, it can create pockets in the gumline that harbor bacteria, in turn causing infections that can actually enter your cat's bloodstream and infect his organs. You can avoid these problems by asking your veterinarian how to clean your cat's teeth at home and getting regular dental cleanings.

Your cat takes in so much of the world through his ears. Next, learn why it's important to check them out.

Checking Your Cat's Ears

Make it a point to check your cat's ears periodically. Grooming time is a good time to do this. Look for a change in color inside the ears. Just like the gums and inside of the mouth, a yellowish or bluish cast to the skin on the inside of your cat's ears can be a sign of a major health problem; alert your veterinarian right away.

Cats do a pretty good job of keeping their ears clean. Outside of some normal wax, then, you shouldn't see much in your cat's ears. Any sort of inflammation, raw skin or crustiness is a tip that something's amiss. Debris in a cat's ear — it usually looks like dirt or coffee grounds -- is an indication of ear mites, tiny insects that live and breed in the ear canal. Itchiness is another sign of ear mites, but not all cats with ear mites will scratch or rub at their ears — and not all cats who scratch or rub their ears have ear mites.


Cats that go outdoors need to have their ears inspected from time to time for other reasons. In cold weather, frostbite is a real danger. Those nice, tall, pointy feline ears are made up mostly of skin and cartilage. There isn't a lot of blood flow to the ears. Even being caught outside for an hour when the temperature takes a sudden drop can be enough for the tips of your cat's ears to freeze.

Outdoor (or indoor/outdoor) cats are also more likely to get into scrapes with other cats. The ears are easy targets for scratches and bites during even the mildest of cat fights. A cat's small, sharp teeth can make a puncture wound that seals up immediately, trapping dirt and germs inside and causing infection. The cat may look and act all right when he comes home, but a few days later an abscess — a tender, swollen area of trapped pus -- may form, and the cat can run a fever. At this point, you'll need to take him or her to the vet.

"The eyes," goes the old saying, "are the windows of the soul." Shift your own eyeballs over to the next section to discover why, for cat owners, the eyes are also a window to how your cat is feeling.

Checking Your Cat's Eyes

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Your cat's eyes can be a window into his health. John Greim/Getty Images

Learning more about your cat's eyes in general can you determine if he's healthy. Let's break down each part of the eye to find out what constitutes normal and what doesn't.

A cat's pupils can look like anything from vertical slits, to the classic spindle-shaped "cat's eye," to full dilation — big black dots that take up all of the colored part of the eye. Certain diseases, including trouble in a cat's nervous system, can cause the pupils to be noticeably different sizes. A cloudy, milky or filmy look to the pupils might be a sign of cataracts, viral ulcers or other vision problems.


The iris is the colored part of the eye. Cats usually have some variety of green, yellow or blue eyes. Occasionally, a cat will be "odd-eyed"; each eye is a different color. If you notice changes in your cat's iris or the appearance of splotches of other colors, contact your vet. It's not unusual for the iris to change with age. Old cats' irises may degenerate and take on dark, freckle-like spots, but this isn’t always a sign of trouble.

The "white" of the eye is officially known as the sclera. Obviously, this should be white (perhaps with some small blood vessels visible). Yellow or "bloodshot" sclera, ulcers or splotches of color, and signs of damage (like scrapes or bruises) are indicators of trouble.

Conjunctiva is the pink, fleshy stuff under the eyelids that helps hold the eye in place. You usually don't notice the conjunctiva unless it swells up, in which case it may protrude from under the eyelid, giving the eye a "meaty" appearance.

The third eyelid, or nictitating membrane, appears when your cat blinks or closes his eyes; this wonderful adaptation moves from the inside corner of the eye to cover the front surface of the eyeball. Again, it's something you rarely notice unless there's a problem. One of the ways cats announce that they don't feel well is when their third eyelids are up — that is, they've moved partially across the eyeball.

If you notice any type of injury or abnormality with your cat's eyes, take him or her to the vet immediately to get it checked out.

Cats run hotter than humans, but that doesn't mean that they can't get fevers. How can you tell if your cat is feeling feverish? Find out next.

Temperature Is an Indicator of a Cat's Health

Ever notice that a cat is particularly nice to cuddle up to on a chilly night? That's because the average body temperature for a cat is 100 to 102.5 degrees Fahrenheit — or 38 to 39 degrees Celsius. Disease — or prolonged exposure to heat or cold — can send a cat's temperature above or below the normal range.

Usually, a mild fever is a normal part of a cat's natural disease-fighting system. But extremely high or persistent fever can do serious — or even fatal — damage, and calls for professional help. You can't really rely on touching your cat to tell if he's running a fever, and you can't get him to hold a thermometer under his tongue. Unfortunately, the most accurate and reliable way to take your cat's temperature is the way he's going to like least — rectally. Of course, your cat isn't going to like this, especially if he or she is already not feeling well. If your cat is already showing signs of being ill, it may be worth trying. If you can manage to take your cat's temperature, it can help to let the vet know that he or she is running a fever before you get to the office.


Obviously, a rectal thermometer is the equipment called for here; you'll want to have a dedicated "cat thermometer" on hand ahead of time. A digital one is best. Lubricate the end with petroleum jelly or vegetable oil. With your cat's feet firmly planted on a secure surface, tuck him or her under one arm with the tail pointed outward and the nose back by your elbow. (This may be a two-person operation.) With the hand of that same arm, hold the cat's tail up, and gently insert the thermometer in the anus with the other hand (you may have to bear down slightly at first). Slowly insert the thermometer about one inch, and keep it there for up to three minutes, if possible. Gently remove the thermometer, wipe it off and read the temperature. Write it down so you can report it accurately to the vet when you call.

Now you know how to examine your cat inside and out, and hopefully, we've given you a better idea of when it's necessary to take him or her to the vet. If you do decide it's time for a visit, you can tell your vet exactly what you've observed, and your cat will be soon be on the road to recovery.

Originally Published: Jun 1, 2011

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