How To Tell If Your Cat Is Sick

Here’s the thing about cats that every owner eventually learns: they’re masters at hiding when they don’t feel well.

You may quickly think that this is stubbornness coming from your cat. But on the contrary, you will learn that this is pure survival instinct wired into their DNA.

In the wild, showing weakness made a cat vulnerable to larger predators.

That’s why learning how to know if your cat is sick matters so much. By the time most cats show obvious symptoms, they’ve often been unwell for days or even weeks.

In this guide, we will walk you through how to tell if your cat is sick by looking at the specific physical and behavioral changes.

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Why Cats Hide When They’re Unwell

VCA Animal Hospitals says cats disguise signs of sickness and pain because showing visible signs of weakness would signal predators that they’re an easy target.

This instinct is so strong that your cat won’t curl up beside you, meowing for attention like a dog might whimper or cuddle up when feeling under the weather.

Your feline friend will more than likely become more silent, seek refuge in a hiding place, or just sleep more.

That survival instinct is also why the American Veterinary Medical Association and other veterinary experts advise biannual wellness exams for adult cats.

By the time signs that your cat is sick become apparent to you, the issue could be quite progressed.

With regular veterinary visits and your own daily observations at home, you can detect issues early, when they’re typically easier (and less costly) to treat.

The good news? With knowledge of subtle changes to look for, understanding cat health problems becomes simple.

Cats tell you how they feel through behavior, appetite, grooming habits, and even sleeping positions. Learn what to look for, and you’ll be ready.

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Physical Signs to Watch For

Visible physical changes can be some of the most apparent cat health warning signs. However, sometimes these changes can be subtle in the beginning stages.

Taking the time to thoroughly check your cat as you pet him every day will help you notice a deviation from the norm.

1. Changes in Eating and Drinking

A decrease or increase in appetite is often one of the first sick cat symptoms feline owners are likely to notice.

If your cat suddenly won’t eat food they previously enjoyed, or if she seems starving all the time, their body is trying to tell you that something’s wrong.

Loss of appetite can indicate feline dental diseases, upset stomach, kidney failure, or cancer.

On the other hand, overeating can be a sign of hyperthyroidism or diabetes, especially when accompanied by weight loss.

Water intake is important as well. If your cat begins drinking significantly more water than normal, they could have kidney disease, diabetes, or hyperthyroidism.

The Cornell Feline Health Center says that excessive thirst and urination are some of the big symptoms that merit a call to your veterinarian.

Likewise, if your cat suddenly refuses to drink, they can become dehydrated. This is dangerous and can happen rather quickly.

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2. Weight Changes

Weight changes are some of the most obvious signs of cat health problems. Cats with chronic disease often lose weight slowly and insidiously.

You may not realize they’ve lost weight until you run your hands along their ribs and spine and discover you can feel every bone.

It’s easy to miss gradual changes when you see your cat every day. Weigh your cat at home once a month to help you notice trends.

Unexpected weight loss is even worse. Slimming down quickly can be a sign of a metabolic disease like diabetes or hyperthyroidism.

Rapid weight gain, bloating or abdominal distention can be caused by tumors, parasites, or excess fluid from heart or liver disease.

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3. Coat and Grooming Changes

Healthy cats are diligent groomers. When they begin to feel ill, one of the first things to suffer is grooming.

If your cat’s coat appears dull, greasy, matted, or unkempt, take notice. There may be more flakes of dandruff evident than usual.

You may discover clumps of loose fur. The cat may seem scruffy compared to normal. Poor kitty cleanliness is a clue that something’s wrong.

Arthritis or obesity may make grooming painful or difficult. Or, the cat may be too weak as a result of the painful condition.

Over-grooming can be a sign of trouble as well. Cats that lick themselves until they are raw develop bald spots.

When your cat is excessively grooming one area, they may be responding to skin allergies, parasites such as fleas or mites, pain (from arthritis or a bladder issue), or stress.

If the skin underneath is raw, red, or irritated, your cat needs to see the veterinarian as early as possible.

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4. Eye, Nose, and Ear Abnormalities

A healthy cat should have clear and shiny eyes. They should also have pupils that are both of the same size.

Symptoms that something isn’t right include droopy eyelids, eye discharge that is green, yellow, or white, squinting, pupils that look dilated or constricted, and pupils that are different sizes.

Keep an eye out for the third eyelid to show. The third eyelid is the clear membrane you’ll see below the lower eyelid.

When a cat isn’t feeling well, they will often raise that membrane, and it will cover part of the eyeball.

Any abnormality in your cat’s eyes can lead to blindness. Contact your vet if you notice something doesn’t look right.

Your cat shouldn’t have nose discharge or dark debris in the ears. Excessive saliva drooling, bad breath, or foul odors should not come from your cat’s body if they’re healthy.

Clear nasal discharge could mean your cat has allergies or that they are developing an upper respiratory infection.

Thick, colored nasal discharge generally means bacterial infection. Bad breath usually is a sign of dental diseas,e but can also indicate kidney disease or diabetes.

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5. Breathing Changes

Healthy cats should breathe through their nose and very little movement should be visible when they breathe.

Respiratory distress, such as shallow breathing, mouth breathing, panting when not exercising, and difficulty breathing, is not always abnormal and usually not an emergency.

Dyspneic cats will frequently stretch their head and neck away from their body and may appear to be unable to find a comfortable position when resting.

Episodes of frequent sneezing or coughing should also be noted, especially if there is an accompanying discharge.

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6. Vomiting

Almost all cats vomit at some point. Eating too quickly is one of the things that causes normal vomiting. But frequent vomiting should never be normal.

If your cat vomits more than once daily, multiple times over a short period of time, or has made vomiting an everyday occurrence for weeks on end, something is very wrong.

Knowing what your cat vomit color means can help you relay important information to your veterinarian.

Also Read: Why Is My Cat Throwing Up Undigested Food?

What Does Cat Vomit Color Mean?

Yellow vomit often includes bile and occurs when your cat’s stomach has been empty for too long. Yellow vomit once in a while isn’t anything to worry about.

But recurrent yellow vomiting may signal liver issues, food allergies, or obstruction of the intestines.

Clear or white foamy vomit most often means your cat simply regurgitated the contents of an empty stomach or esophagus.

Brown vomit usually is partially digested food. However, if it is very dark brown, it could be digested blood originating in your cat’s stomach or upper intestinal tract.

Either scenario is cause for concern, so you should seek the services of a veterinarian immediately.

Green vomit may simply mean your cat ate some grass or plants. However, it can also signal backed-up bile or poisoning.

If you notice any cat vomit with bright red blood in it, we recommend you talk to your vet immediately for follow-up.

Cat Vomit Color Chart

Color	What It Means	Possible Causes	Action
Yellow / Bile	Empty stomach, bile buildup	Skipped meals, bilious vomiting syndrome, liver issues	Monitor
Clear / White Foam	Empty stomach, saliva & acid	Hairballs, indigestion, eating too fast	Monitor
Green	Bile or plant material	Grass/plant ingestion, intestinal blockage, toxins	See Vet
Brown	Partially digested food	Food intolerance, GI issues, ate something bad	See Vet
Red / Pink	Fresh blood present	Mouth injury, ulcers, foreign object, internal bleeding	Urgent
Black / Coffee Grounds	Digested blood	Stomach/intestinal bleeding, ulcers, serious illness	Emergency

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7. Litter Box Changes

Reduced urine volume, straining to pee, blood in the urine, or multiple visits to the litter box with little urine produced can all be signs of a urinary problem.

These could also be signs of urinary obstruction, and it is especially an ENT life-threatening emergency in male cats.

Straining to urinate in the litter box is far more likely to be caused by urethral blockage than constipation and requires immediate veterinary attention.

Even your cat’s poop can change. If they have diarrhea for more than a day, are constipated, have very dry or hard stools, or if they aren’t brown, you should take note.

And kitty may not be acting naughty if they suddenly start avoiding the litter box and going somewhere else.

Your cat may be creating a new toilet spot because they hurt when using the litter box. The cat could have a bladder infection, constipation, or arthritis pain when getting in and out of the box.

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8. Mobility Issues

An arthritic cat will stop jumping on their favorite chair, may pause before jumping, or alter the way they climb walls and fences. Arthritis comes on slowly and is often shrugged off as old age.

However, if your cat suddenly loses use of their hind legs, seek emergency veterinary care – this may be a sign of a blood clot or injury to the spine.

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Behavioral Changes That Signal Illness

Behavioral changes can sometimes be the most significant signs your cat is sick. You know your kitty and her habits better than anyone. If those habits change, take notice.

1. Hiding and Withdrawal

Sick cats often become depressed and isolate themselves, though this behavior will differ based on your cat’s personality.

Other cats may become needy and want constant attention when they feel ill. Still others may only become mean or want to be left alone.

The important thing is knowing how your cat differs from his normal self.

If your social cat doesn’t want anything to do with you, or your independent cat refuses to leave you alone, these are both signs of cat behavior warning signs.

2. Aggression or Irritability

If your normally sweet cat suddenly starts hissing, swatting, or biting when you touch them, then these could be signs of pain in cats.

Cats will flinch when touched in painful areas, grow aggressive when you try to pick them up, or not let you pet them at all if they are hurting.

3. Vocalization Changes

Some cats are naturally talkative, and others hardly ever speak. Shifts toward either end of the spectrum may be signs of disease.

Excessive meowing or yowling, particularly at night, may be due to pain, cognitive dysfunction disease in older cats, or hyperthyroidism.

A cat who is normally very vocal may be suffering to the point that they cannot talk. Hoarseness, raspiness or loss of voice should also be investigated.

4. Sleep Pattern Shifts

Cats sleep anywhere from 12 to 16 hours a day. Therefore, sleeping excessively may not be a reason to panic.

However, if your cat sleeps all the time and has no energy to play for even a few minutes at a time, or seems sluggish and weak when awake, you need to be concerned.

Cat sleeping positions when sick can indicate problems too.

Vets get concerned about how your cat sleeps if they experience restless sleeping or sleep in awkward positions, says Dr. Jacqueline Brister, DVM.

If your cat is hurting, they may sleep in positions where they’re hunched over, avoiding putting pressure on a sore limb, or asleep seemingly because they don’t want to be touched.

Curled up tightly like a ball with the head tucked in is a common sleeping position for a sick cat. It’s an attempt to hold onto body heat and cover up vulnerable areas.

Sleeping in hiding places, like under beds, closets, or in dark corners, is another indication your cat feels the need to protect herself when vulnerable.

Call your veterinarian if your cat suddenly begins sleeping in her litter box. This behavior usually signals urinary or digestive discomfort.

5. Loss of Interest in Play

Older cats still enjoy play. If your cat seems disinterested in favorite toys or fails to react to the flutter of the feather wand, they are telling you something isn’t right.

Decreased interactive activity and interest are two of the most prevalent early signs of sickness in cats.

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Specific Health Conditions to Know About

Getting to know some of the most common illnesses in cats helps you recognize patterns and communicate effectively with your veterinarian.

1. Upper Respiratory Infections (Cat Colds)

Curious about how to treat a cat’s cold? Healthy cats can catch something very similar to a cold that humans get.

It’s called a feline upper respiratory infection, and while it’s very similar to our colds, the treatment is quite different.

Feline upper respiratory infections are caused by the viruses known as feline herpesvirus and calicivirus.

The infections are very contagious among cats and cause symptoms such as sneezing, runny nose, watery eyes, congestion, mouth ulcers, and fever.

Most infections clear up in one to three weeks with supportive care at home, but cats may require vet care if they stop eating or if they have trouble breathing or become extremely congested.

Treatments from your vet can include administering fluids. Some cats may have to be hospitalized.

If your cat has contracted feline herpesvirus, your kitty will have the virus for life. He may have outbreaks when he’s feeling stressed.

2. Kidney Disease

Kidney disease is one of the most common cat health issues we see today, particularly as cats become older.

Increased thirst and urination, weight loss, decreased appetite, and occasional vomiting are early symptoms. Kidney function diminishes slowly, so symptoms can be mild initially.

Kidney disease can often be detected on bloodwork before you see any clinical symptoms, which is why your biannual wellness visits are so important, especially for cats older than 7.

3. Diabetes

Feline diabetes symptoms are very similar to the human version. An affected cat will drink and urinate excessively, lose weight even with a good appetite, and become lethargic.

The ASPCA warns that untreated diabetic cats can develop kidney disease, neurological disorders, or other metabolic conditions.

Diabetic cats usually need insulin shots, although some may respond better with diet changes alone.

4. Hyperthyroidism

Hyperthyroidism, or overactive thyroid disease, is one of the most prevalent conditions seen in middle-aged and senior cats.

Weight loss with an increased appetite, restlessness or hyperactivity, increased thirst and urination, vomiting, diarrhea, and unkempt haircoat are common signs of hyperthyroidism.

Hyperthyroid cats will often become increasingly restless at night, sometimes howling and waking up family members.

Fortunately, hyperthyroidism is treatable with medication, a special diet, or special radiation therapy. One simple blood test can confirm hyperthyroidism.

5. FeLV and FIV

Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are serious cat diseases that compromise the immune system and make cats susceptible to secondary infections.

On how to identify FeLV in cats, diagnosis can be difficult because cats are often asymptomatic in the early stages of the disease.

As the illness progresses, Cornell Feline Health Center explains that cats with FeLV will progressively fail.

This can manifest in decreased appetite, weight loss, poor coat condition, fever, pale gums, skin infections, bladder infections, and respiratory infections.

FIV is also sometimes referred to as feline AIDS. Cats usually become infected through bite wounds inflicted during territorial disputes.

Dr. Julie Levy, DVM, of Cornell University says, ‘the most frequently seen clinical signs of FIV infection are stomatitis (inflammation of the mouth and gums), uveitis (eye inflammation), and cancers’.

Cats who are infected with either virus can survive many years when properly cared for. Indoor living and separating them from cats who do not have the virus is advised.

6. Urinary Issues

Feline lower urinary tract disease refers to a few different disorders that affect the bladder and urethra. Some cat virus symptoms and feline urinary problems can coincide.

If your cat is stressed or immunosuppressed, they’re more likely to experience urinary tract issues.

Straining to urinate, frequent litter box usage, blood in urine, urinating outside the litter box, and licking genitals are all signs of a urinary problem.

Keep in mind that male cats can experience a life-threatening blockage of urine flow. If your male cat is straining to pee and not passing much urine or any urine at all, seek vet care immediately.

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Kitten-Specific Concerns

It is important to know the signs of a sick kitten because kittens are much more fragile than full-grown cats.

They have weaker immune systems, have few reserves in their bodies, and many ailments that an adult cat can fight off can be deadly to a kitten.

Health problems that may never be detected in an adult can cause fatality in a kitten within hours.

Kittens are vulnerable to upper respiratory infections, fading kitten syndrome, fleas, intestinal worms, and dehydration from vomiting or diarrhea.

Fading kitten syndrome is the failure of a kitten to thrive within the first four to five weeks of life. Treatment is a medical emergency and requires prompt veterinary assistance.

If you are learning how to take care of sick kittens, having the knowledge of when to take them to the veterinarian is very important.

Take kittens to the veterinarian immediately if they haven’t eaten in over 12 hours, seem weak or lethargic, or have a cool body temperature.

Other symptoms include pale gums, having trouble breathing, having severe diarrhea or vomiting, or not gaining weight appropriately.

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What to Do While You Wait for the Vet

After noticing signs cat is sick and booking a vet appointment, you may be curious how to care for a sick cat. Try these safe methods to help support your kitty.

Start by designating a quiet and comfortable area. Many ill cats will try to hide. That’s perfectly fine, don’t try to disturb them.

Ensure they can reach food, water, and a litter box easily. They shouldn’t have to move far or use stairs to reach these essentials.

Provide a warm and calm environment. Limit stressors such as loud noises, visitors, or other pets pestering them.

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What to Feed a Sick Cat

Here are more cat-friendly foods you can feed your cat to assist their recovery journey. Remember not to include garlic and onions on homemade diets.

• Plain boiled chicken
• Plain boiled turkey
• Plain white rice
• Plain pumpkin puree
• Chicken baby food
• Boiled fish
• Low-sodium chicken broth
• Scrambled eggs
• Cottage cheese
• Prescription veterinary recovery diet
• Wet canned cat food
• Cat-safe bone broth
• Cooked sweet potato
• Plain cooked oatmeal

When looking for the best food for sick cats, you should know that enticing them to eat is often more important than the food you offer.

If your cat has an upper respiratory infection, smell is often gone. Try heating the food a little to help release aromas.

For cats with respiratory infections, try running your cat a hot shower and sitting with them in the steamy bathroom for about 10 – 15 minutes.

This can loosen up any congestion. Wipe away any discharge from their eyes or nose with a warm, wet cloth.

Disclaimer on cat friendly over the counter medicine! Did you know that many medicines made for humans are deadly for cats? These include acetaminophen (Tylenol), ibuprofen, and aspirin.

Please consult your veterinarian before administering anything to your cat, even cat meds purchased over the counter.

Your vet should always know what your cat is taking because there can be interactions with other medicines they may need to administer.

As far as how to treat sick cats at home, the best medicine is supportive care. That is lots of love, hydration, and food, and leave the treatment to the professionals.

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Final Thoughts

As you have seen, knowing how to recognize cat illness is about spotting the normal shifts in your cat’s everyday activities.

Cats can be so good at hiding their feelings, but if you’re keen, it shouldn’t take you a while to know they’re not feeling well.

With this cat illness symptoms guide, we hope you have understood the physical changes and behavioral changes that show your cat’s health status. 

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