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Home > Cats > 17 Signs that Your Cat May Be Sick (Vet Answer)

17 Signs that Your Cat May Be Sick (Vet Answer)

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Dr. Paola Cuevas Photo

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Dr. Paola Cuevas

Veterinarian, MVZ

The information is current and up-to-date in accordance with the latest veterinarian research.

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Unlike children or humans, pets cannot speak to tell us when something is not quite right. On top of that, cats are professional “disease maskers.” As part of their survival strategy, cats have evolved to hide any sign of disease. Showing illness makes a wild animal vulnerable to predators and members of the same species competing for resources. This characteristic is still present even in modern house cats.

Since it is not always easy to know when your cat may be sick, learning to recognize signs of disease is a crucial part of owning cats. One of the worst mistakes a cat owner can make is waiting to see the signs of illness pass because in the case of sick cats, if you notice it today, tomorrow might be too late.


Know Your Cat

Knowing your cat’s personality, physical aspects, routines, and behavior can help you catch early signs that something is not quite well. Being observant and familiar with your cat’s normal state is the first step in recognizing the signs that your cat might be sick. In the following guide, we will review 17 signs, going from very obvious to not so obvious, and give you tips on how to improve your level of awareness of what is normal for your cat.

tired sick cat
Image Credit: natata, Shutterstock

The 17 Signs That Your Cat May Be Sick

1. Cat Refusing to Eat

A cat that is not accepting any food clearly indicatesthat something is not right. Although slight changes in appetite can be considered normal, a cat refusing to eat needs attention. Cats not eating will tapper on their fat reserves for energy and develop a dangerous condition called hepatic lipidosis, especially if they are overweight. If your cat is not eating, don’t hesitate and take it to the vet before the case complicates.

2. Cat is Limping

A limping cat is a clear indication of pain or discomfort. The limp could be caused by a minor wound, a foreign object, a fracture, or arthritis. If your cat is limping, it is best to make a visual inspection to see if you can recognize any apparent injury or foreign object that might be easy to remove. But if there is nothing very obvious, then the right thing to do is bring the cat to the vet for further investigation.

3. Cat is Drinking More Water

In general, it is challenging to get cats to drink water as they should get a good part of their hydration from the moisture content in their prey. Cats on a dry food diet should be encouraged to drink water and ideally be changed to a wet diet. However, if you notice that your cat is drinking more than usual or drinking from unusual sources, such as a hose or the toilet, this could be a sign that something is wrong.

Endocrine disorders, such as diabetes and thyroid issues, cause increased thirst. Endocrine disorders are fairly common in older cats, and unfortunately, we also see a lot of cats developing diabetes due to the higher-than-normal carbohydrate content in most dry cat foods. If your cat has suddenly started drinking more water, bring it to the vet for bloodwork to identify the issue.

Maine coon cat drinking water with tongue from tap
Image Credit: GrashAlex, Shutterstock

4. Cat Urinating More Frequently

If a cat seems to be urinating more frequently, it could be an indication of painful urination. Cats suffering urinary tract infections or stones experience pain when urinating and usually urinate in smaller quantities but more frequently.

Blood in urine or no urine at all is a clear indication that you must take your cat to the vet urgently. This is especially important in the case of male cats. They tend to develop ureteral obstructions, which can become fatal in as little as 24-48 hours if left untreated.

5. Cat Refusing to Use the Litter Box

If a cat refuses to use the litter box, this could also indicate painful urination. Urinary tract infections, bladder stones, and kidney disease are common causes of a cat changing its litter habits.

6. Cat With Diarrhea

Gastrointestinal infections, food sensitivities, stress and anxiety, and irritable bowel syndrome are just a few of the many possible causes of diarrhea in a cat. If your cat is suffering diarrhea, it is at risk of becoming dehydrated, so it is best to find the cause and treatment soon. Waiting to see if it improves could end up increasing the vet’s costs, as a dehydrated cat is at risk of organ damage and will most likely need to remain in the clinic for IV fluid therapy.

british shorthair cat in litter box
Image Credit: Nils Jacobi, Sutterstock

7. Cat Vomiting

Regurgitation of hairballs is considered normal in cats, and some cats sporadically vomit after eating. However, a cat with frequent vomit is at risk of dehydration and needs medical attention. Infections, liver disease, intestinal blockages, and even cancer could be the cause behind your cat vomiting frequently. This needs to be investigated to prevent complications and start timely treatment.

8. Cat With Nasal or Ocular Discharge

Cats with respiratory infections or eye infections present abnormal mucous secretions. Respiratory tract infections are usually accompanied by other signs, such as sneezing, whizzing, or coughing. It is best to see a vet for advice and treatment before infections worsen. Follow the veterinarian’s instructions and remember that it is best to isolate cats with contagious infections to avoid transmission to other pets.

9. Lack of Energy

If your normally active and playful cat suddenly looks lethargic and uninterested, this is a clear sign that it is feeling unwell and needs a trip to the vet.

cat splooting on the ground sleeping
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10. Changes in Grooming Habits

Normally, cats are clean creatures when it comes to their grooming habits. Cats feeling unwell will dramatically decrease the frequency of their grooming or completely stop grooming. If you have noticed less than normally grooming or your cat’s fur looks greasy, matted, unkempt, or with dandruff, this is a sign something is going on. This could be from a skin infection to arthritis. Start investigating possible causes and get professional advice from a vet.

11. Cat is Losing a Lot of Hair

If you notice more fur than usual all over your carpets and furniture, you need to be sure this is due to normal shedding and not a medical condition. Alopecic areas are not normal in cats, and they could be caused by skin irritations, infections, or allergies.

12. Cat Has Developed a Stinky Breath

A cat with a stinky breath is usually an indication of periodontal disease or some infection in the mouth and needs to be checked by a veterinary dentist for a clean and treatment. Having consistent tooth brushing habits should normally help you prevent these situations, but once the cat has developed them, they require immediate attention.

13. Cat Has Lost a Lot of Weight

Many diseases can cause a cat to lose weight. Parasites or diabetes could cause a cat to lose weight, regardless of eating normally. Other forms of disease decrease a cat’s appetite and result in weight loss. If you have noticed any of those scenarios without knowing that you have purposely put your cat on a diet, take your cat to the vet to start investigating what is causing this weight loss.

14. Cat Hiding

Some cats that are fearful or anxious tend to hide, but so do cats in pain. Study the scenario but if your normally social cat has been avoiding you, this is another not-so-clear sign that something is going on.

black and white cat hiding under the bed
Image Credit: Robert Way, Shutterstock

15. Cat Becoming Aggressive

Changes in hormones and poor behavioral management can cause cats to become aggressive. However, many injured or sick cats become aggressive as a response to discomfort when being handled or as a way to get attention.

16. Cat Becoming More Vocal

Increased vocalization is a cat’s way of demanding food and attention. But if your cat becomes louder and very vocal for over 24-36 hours, regardless of food availability, this could be your cat’s way of trying to communicate that something is not right.

That said, females in heat become louder and more vocal, so all factors need to be taken into account to understand what is causing this behavior. Some neurological problems can cause increased vocalization in cats. Plus, cats suffering from hearing or vision loss will also vocalize more.

17. Cat Not Jumping to Places It Used To

This might not be a very obvious sign, but if you are a good observer and you have noticed that your cat is no longer hanging out in that higher-up bookshelf it used to love, this could be the development of arthritis or an injury.



Hiding signs of disease has been a feline’s survival strategy that is still prevalent in our modern cats. Being aware of the signs of a sick cat can go a long way in preventing complications and potentially saving your cat’s life.

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Featured Image Credit: one photo, Shutterstock

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