Cat Illnesses: Symptoms to Watch For

Cat Illnesses are too often diagnosed late in the course of the disease. Many loving cat owners wait too long to take their kitties with feline illnesses symptoms to the veterinarian. The results are suffering pets, heartbroken owners, and a higher financial cost. The goal of this page is to help you go beyond the obvious signs of an emergency to include the more subtle symptoms that your kitty is in big trouble if you don't head for the veterinarian right away.

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Cat Illnesses have symptoms that you can usually recognize at home, the earlier the better. You probably think it's a complicated process to learn about the various aspects of cat anatomy, physiology, cat behavior, and feline diseases. It is, if you want to learn everything. However, you certainly do not have to be a veterinarian to be able to recognize signs of cat illnesses in your own cat. It's rather simple, actually, once you learn the basics.

In spite of that, the most painful part of my career has been thesadness I have experienced on far too many occasions when a loving owner brings their precious sickkitty to see me or writes to me on this website when the cat should have been examined by a vet much earlier. Too often, a cat is brought to me for examination too late. At those times, knowing that I could have saved their beloved cat's life had I examined him a month or week or even a day earlier is difficult for me to face and heart-wrenching for the owner. In most cases, it has also meant prolonged suffering for the cat.

two cat brothers
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From these experiences, I have come to the conclusion that while recognizing signs of cat illnesses is easy to learn, it is not common sense. It does, in fact, have to be learned, and this page will teach you what you need to know.

To the left, on the navigation bar, you can find additional pages on specific symptoms. If your cat is showing specific symptoms of cat illnesses, such as vomiting, you may want to refer to one or more of those pages. However, I strongly recommend that you read this entire article for more information about what is "normal" and "not normal" for cats. As a cat parent, you need to be able to recognize anything that may indicate your kitty is ill and you need to recognize it early!

In order to fully understand your cat's illness symptoms, we need to talk about the basic anatomy of a cat. I promise it won't be anything too complicated ...just be aware that cats have the same organs you and I do, including kidneys, a liver, lungs, a pancreas, large and small intestines, a colon, a bladder, a heart, etc. ...and these organs are almost identical to ours in function and malfunction.

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Introduction to Cat Anatomy and Feline Medications

Don't stop reading! I know the word "anatomy" strikes fear in many pre-med or pre-vet students' hearts and may in you, also. However, the anatomy that you need to learn about your cat is very simple. In fact, you probably know most of it already, but may not be aware that you know it.

Many of my clients over the past 20 years have been surprised to learn that cats can get just about every disease that affects people. It's true, and it really shouldn't be surprising if, as I mentioned above, you know that cats have essentially the same organs that you and I have. If they have the same organs that we do, then it's just another simple step to realizing that those organs can malfunction the same way ours do and produce cat illnesses that are almost identical to their human counterparts.

For example, people develop diabetes because there is a problem with their pancreas. Cats have a pancreas, so naturally they can develop cat diabetes, too. People become hyperthyroid because they have a thyroid gland and it malfunctions, producing excess thyroid hormone. Hyperthyroidism in cats is also one of the common cat illnesses because they have thyroid glands that can malfunction. And the same goes for kidneys in cats. Feline kidney disease and kidney failure are just as possible, and can even present with similar symptoms, as renal problems in humans.

white cat with green eyes
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There are ailments that affect cats that do not have equivalent counterparts in humans, such as cat hairballs. Can you imagine coughing up one of those? Or needing cat flea treatment? Thank goodness we don't have to endure such things, but our feline friends shouldn't have to either. With your knowledge about cat symptoms and good preventative care, they don't have to.

There are other cat illnesses, such as heartworm disease, feline FIP and feline leukemia which can be harder to recognize easily because we don’t have a human comparison. However, if you learn the general early signs of cat illnesses, you will get your kitty to the vet earlier, resulting in earlier treatment and a better prognosis.

Before talking about the specific symptoms of cat illnesses, I have to emphasize how very important it is to know one very serious fact about feline medications.

While the medications that are needed to treat a sick cat are often the exact same medications that we take, some human medications or even old-fashioned cat remedies are very dangerous. You can kill your precious feline friend if you give your cat any medication without the direction of your veterinarian!

Please keep this in mind as you examine your cat for symptoms of cat illnesses and monitor his overall health. Although cats can have many of the same diseases that we do, that does not mean that cats can be treated with the same medications or same dosages. As one quick example, medications that are used frequently for human pain such as Tylenol or Advil or aspirin CANNOT be given for cat pain. These medications can kill your kitty quickly!

External Cat Anatomy

If you look at your cat from head to tail, you'll see

normal cat posture

(1) Ears
(2) Eyes
(3) Nose
(4) Mouth and Chin
(5) Neck
(6) Fur
(7) Skin
(8) 4 Legs
The front two cat legs are very much like our arms while the back two are very much like our legs. They have the same bones and same joints, including shoulders, elbows, wrists, hips, knees, and ankles. Our hands are their paws --- even our fingers have the equivalent in cats, with three bones and a nail projecting from the distal most bone.
(9) Back, Chest area, and Lower abdominal area
(10) Anus and Rectum
(11) Penis or Vagina, both with a urethra through which urine is excreted
(12) Tail

Examining Your Cat Externally

I have a system I have used in my practice for 20 years that will make your cat health evaluation at home easy and quite simple. Examine your cat's body by always starting at the head and continuing down the body to the tip of the tail. If you do it the same way every time you examine your cat, it will become like second nature and you won't miss anything.

The most important thing to know is how all the parts of a "normal" cat's body look. You need to know what’s normal obviously before you can know that something is abnormal. Once you know normal, anything different is worth questioning your vet about.

From head to tail tip, look at the following.

clean healthy cat ear

(1) Ears

Look at your cat’s face straight-on and compare the two ears. Are they both standing up and uniform in size and shape? Now, look inside each one under good lighting conditions. Are they the same inside? Are they pink? Do they smell? (They shouldn’t.) Are they perfectly free of wax or other debris? (They should be. Most of the time, healthy cats have incredibly clean ears.)

To check your cat’s hearing, stand behind the cat, making sure that he absolutely can’t see you and clap loudly. He should turn around or jump or at the very least, flick his ears quite obviously.

(2) Eyes

Again, while looking at your cat’s face straight-on, determine whether the cat's eyes are the same size. Are they shaped the same way? Are the pupils (the black center) equal in size? They should be. Are the pupils easy to see or is it at all cloudy in front of them? (It shouldn’t be.)

The cornea is the clear “covering” of the eye that you really shouldn't see at all as you are looking at the pupils. Is it cloudy instead? Are there blood vessels obvious on the cornea? (There shouldn’t be.)

normal cat eyes

If you shine a bright light in one eye, do the pupils in both eyes get smaller and are they the same size? They should be. When you take the bright light away, do they both get larger and, again, are they the same size?

If you move your finger back and forth to the left and right does your cat follow your finger with both eyes? How about up and down? If you throw a cotton ball a small distance away, does your cat see the cotton ball? The answer to all these questions should be "yes".

normal cat eyes dilated

Are the inner corners of the eyes clean? Is there any discharge coming from the eyes? There shouldn't be. Is your cat squinting? Do the eyelids look at all swollen? Is the “3rd eyelid” visible? The 3rd eyelid shouldn't be seen, but certain cat illnesses or eye conditions will result in it being seen as a white membrane coming from the inner corner of the eye(s).

It is very possible for a cat to lose its sight and the owner not know. I have had several clients come in with their cat and tell me that he sees just fine because he makes his way around the house and never bumps into anything. Yet, when I check the cat’s eyes and vision, he is completely blind.

How is that possible? Cats are able to so quickly adapt and find their way around familiar surroundings, that as long as nothing is out of place in the house, you may never know they’re blind.

To make sure your cat can see, you can use the cotton ball trick. You also should place a chair or other object in the middle of the room, call your cat to come to you and see if he goes easily around the chair or bumps into it.

If any of the above factors seem a bit off to you, reading more about cat eye health and cat eye infections and other cat illnesses would be recommended.

(3) Nose

cat nose and whisker
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Looking at your cat’s face again, are the nostrils the same size? Are they free of discharge or debris? Is there any swelling of the nose? Does your cat breathe quietly or can you hear noise when he breathes? Is your cat's nose pink? Is he sneezing? These are all questions you should ask yourself.

(4) Mouth

Examining a cat’s mouth can be very difficult. I certainly don’t want you to get bitten while doing it. IF you can, you should gently lift the upper lip on one side and look at the gums and teeth. Are the gums pink, not red or white? If they are red and inflamed looking or very pale or white, that is cause for concern. Are the gums moist? They should be.

Are the teeth white? If they’re not, they have a build-up of plaqueon them. Cats need their teeth professionally cleaned just as we do. Dental care for cats has been much over-looked in the past and is SO necessary. Taking care of your cat's teeth is important not only for the comfort of your cat, but to prevent spread of infection to other organs of the body. If you can only see a couple of teeth and they look ok, please don’t assume that all the teeth are fine. If you can’t see both the sides and front of the upper and lower teeth and your cat’s teeth haven’t been examined by a veterinarian in the last year, it is time to make that appointment.

If your cat lets you open his mouth easily, try to get a peek at his tongue as well. Are there ulcers? Is it a healthy, normal pink color? Is the thickness uniform or is any part of the tongue harder and thicker than the rest?

cat gum infectio
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If you see swollen, red gingiva or large chunks of tartar on the teeth (as in the picture to the left) or notice that your feline has bad breath, it is time to get to the vet. Feline gum disease is one of the preventable and treatable cat illnesses if caught early. It can also be one of the feline illnesses symptoms that indicates another internal disease is present that needs attention.

(5) Chin

Feel and look at your cat’s chin for two reasons primarily.

normal cat chin and nec

Rub your hand along the bony ridges of the chin and note whether they feel the same and there’s no prominent hard thickness on one side that’s not on the other. Cat cancer of the jawbone is possible and easy to miss when your cat is showing no other signs of cat illnesses.

Does the skin covering the jawbone feel smooth and free of bumps? If there are little bumps or redness and hair loss, your kitty may have feline acne and need to see the vet.

(6) Neck

Just rub your hands gently all over your kitty’s neck, underneath and on top. Feel mainly for symmetry and lumps and bumps. If you feel something on one side that is not on the other, it may be cause for concern.

(7) Cat Fur and Skin

A cat’s skin and fur often reflects his general state of health and well-being. Is the fur intact or are there areas of hair loss? Don’t check just the obvious places, but look up and down the legs and on the belly and the tail and under the tail.

normal healthy cat fu

Check every inch of your cat’s body looking for hair loss or irritated skin and feel for lumps and bumps and scaly areas. Every cat owner should own a flea comb and comb through the fur in several different places on the body, checking for fleas or for black “flea dirt”.

Is the fur soft and shiny and not too oily or not too dry? Are there white flakes of skin on the hair coat, particularly in front of the tail? "Dandruff" can be a sign of many different underlying cat illnesses or can be caused by inadequate grooming. Is there evidence of matted cat fur anywhere on the body? Both dandruff and mats need attention and can be uncomfortable for your kitty.

(8) Legs

Watch your cat walk and jump. Does his gait look the same as always? Cats walk on what is the equivalent of our toes (see the picture on the left below). If your kitty is suddenly not doing that, but instead is walking down on his “heels”, as in the picture on the right below, an immediate visit to your vet is in order. That is one of the hallmark feline diabetes symptoms.

normal cat stanc
cat neuropath

Also, check that your kitty can jump up and down from the sofa or bed as usual and climb stairs if he has been climbing stairs. Because cats have joints, just as you and I do, arthritis and other joint or bone cat health problems are just as possible.Definitely check each of the 4 paws if your cat will let you. The pads of your cat’s feet should be pink (unless your kitty’s pads are black genetically). If your cat is not declawed, make sure the nails are not so long that they’re starting to curl under and grow into the pads. If that happens, a nasty abscess and infection can occur. If your cat IS declawed, check that there is no regrowth of the claws. It can happen and can be very painful and need vet attention.

The paws should be uniform in size.

(9) Back, chest, and abdominal areas

Feel the backbone of your cat. Is it more prominent than it used to be? That can indicate weight loss. And any amount of weight loss can indicate one of many cat illnesses. A digital scale is a great thing to keep around so you can weigh your cat at least once monthly.

Especially check the nipples in the skin of your cat’s abdomen. Remember males have them as well and while it’s rare, males can get cat mammary cancer, too. Make sure they are all similar in size, shape and color, including the area of skin around each one.

cat tai

(10) Urogenital and Anal Regions

Look at the urogenital and anal regions on your cat. Is there any discharge? Is there feces or anal sac material stuck on the cat or mats that are inhibiting normal defecation? Is there redness or inflammation? Has your kitty shown any signs of cat diarrhea or constipation?

(11) Tail

Last, but not least, run your hands the full length of your cat's tail, feeling the cat fur and skin and the underlying bones. Cats can have broken tails, nasty skin infections, lacerations on their tails, or even ringworm.

We have just covered a fairly complete external exam of your cat from head to toe. If it seemed time-consuming or difficult, keep practicing. It will get quicker and easier. With a little practice and change in your thinking so that you instinctively look at your cat like this all the time, you'll notice changes more quickly and help your kitty be healthy and comfortable and avoid serious cat illnesses and maybe even save his life.

Internal Cat Anatomy

Knowing what is going on inside your cat may sound much more difficult than checking your cat externally. Of course, we all know that the internal organs can't be seen or directly examined. However, in some ways, it’s much easier to examine your cat internally through external symptoms.

While you can’t actually do an internal exam or see x-rays or ultrasound images of your cat without going to the veterinarian, you can get a wealth of information from the small number of things that you can determine. There are certain feline illnesses symptoms that are easy to recognize just by watching your cat go through his daily routine.

As I mentioned earlier, cats have internal organs similar to our own. Among the most important internal organs of cats are

two cat

(1) Brain
(2) Heart
(3) Kidneys
(4) Thyroid Glands
(5) Urinary Bladder
(6) Gall Bladder
(7) Liver
(8) Uterus or Testicles if the cat is unaltered
(9) Lungs
(10) Pancreas
(11) Spleen
(12) Stomach
(13) Intestines (small and large)

If you know the most common, visible symptoms of malfunction of these organs, you can take your cat to the vet earlier rather than later in the course of a disease. Many, many cat illnesses are very treatable. Many can be cured or can be managed with very little difficulty for long periods of time, even years. Without treatment, many of these same diseases can kill your cat.

What are the most common symptoms of cat illnesses?

They actually are simple and very easy to remember. There's only six things to watch for and they are all right in front of you.

Just think of the six main things your cat does.






*Behave normally

Those are the most important behaviors you need to watch to know if your cat is most likely healthy.

Simply ask yourself the following questions each day.

(1) Is my cat eating more or less than usual? Also, is my cat throwing up?

(2) Drinking more or less?

(3) Urinating more or less?

(4) Having more frequent or less frequent bowel movements, and is the stool harder or softer?

(5) and (6) Last, but not least, has my cat's activity level changed? Is he sleeping the same amount and acting the same as usual when he's awake? Or is he sluggish, less active, and sleeping more? OR is he more active than usual? One of the signs of hyperthyroidism in cats is increased activity. Older cats that normally would be sleeping most of the time may act more like younger cats. Owners often think that is great and that their cat is healthy when it's really a sign of a very dangerous, but treatable disease.

If any one of those functions change, observe carefully, even take notes, and call your vet right away. It could be nothing OR it could be early feline kidney problems, diabetes, hyperthyroidism, a caturinary tract infection and a few other things, 99% of which can be cured or controlled IF CAUGHT EARLY.

It's worth repeating those 6 things one more time. Appetite, Thirst, Urination, Bowel Movements, Activity Level and General Behavior. Pay close attention to those bodily functions and behavior of your cat. Your observations are free and your vet bill cheaper when disease is diagnosed and treated early, but the value when your observations save your cat's life.....PRICELESS!


To summarize, cat illnesses are just like human illnesses, and symptoms of cat illnesses are therefore similar to the symptoms exhibited by people under the same conditions. The important thing is that you learn what cat illnesses symptoms are and how to recognize them. Also, feline medications are often the same as the meds we take, but NEVER give your cat your own medication without consulting your veterinarian.

tiger cat fac
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Several of the major cat illnesses, especially those most commonly seen as elderly cat health problems, can have very similar symptoms. But don't worry. Remember, it isn't your job to diagnose your cat! Your job is to determine if and when your cat needs to be examined by a vet.

Your vet will be able to diagnose your cat, if you notice any of the symptoms of cat illnesses, by conducting a thorough exam and usually running some blood work. And, because cats have the same organs we do, similar technology to human diagnostic medicine, such as x-rays, ultrasounds, MRIs, and urinalysis, are available for cats as well, and may be needed to diagnose certain cat illnesses based on the symptoms you've observed.

Please remember that your cat's chances of being helped are much greater AND your expenses much less if you go to the vet at the first sign of something unusual.

There’s much more to learn about the individual conditions and diseases your kitty can face, but if you learn the feline illnesses symptoms to watch for in order to detect cat illnesses early, you AND your cat are way ahead of the game. I would much rather practice preventative medicine or diagnose sick cat symptoms while the condition is still early and treatable rather than finding out that it's too late. I'm sure that's what you would like, also.

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