8 signs of sickness in cats

Posted on Posted in Blog

by: Elaine Chiam, Love Kuching Project
done as a presentation for NTUCMN


We normally seek our gut instinct to determine if our hall cats – or our pet cats – are ill or in danger. But sometimes gut instinct might not be enough – cats can’t tell you if they feel sick or not, no matter how well you meow.

Here are eight signs of sickness in cats that can help recognise if a cat is injured or ill:

Behavioural changes


Cola, a cat from Hall 4. Cola is usually shy, and hides when she sees new visitors.

Cats are territorial and consistent animals. They may not be creatures of habit, but they are creatures that usually behave in a set manner. 

Behavioural changes can thus be relatively easily detected in a cat, provided if you know the cat well. If your hall’s cat is sleeping most of the time and you find it sleeping at your hall’s stairwell – provided it is where it usually sleeps – that would be normal behaviour. If, however, the cat is usually active and pacing around all the time – and you find it to be hiding and lethargic, there may be a problem.

Aggression may also be a clue. Sickness is weakness – and cats in nature would tend to hide such weaknesses by protecting itself against enemies and predators. Hence, a sick or injured cat may be more aggressive. If, for example, the cat is usually very shy or feral, then aggression may be a usual occurrence. 

The same would apply for hiding, shy cats – if a cat is usually shy, hiding may be part of its usual behaviour. Something will be wrong, however, if a cat that is usually friendly turns shy.

Third eyelid visible


Scooter, one of Love Kuching Project’s resident cats, in 2010. The white part is a visible third eyelid. (photo: Love Kuching Project)

The third eyelid, also known as the nictitating membrane, is present in certain animals, such as cats. When the third eyelid is visible on the inside corner of the eye, it is protruding, and a sign of sickness. The membrane will also be visible when the cat has undergone anaesthesia. 

In some cases, however, the third eyelid may also be visible when the cat is relaxed and resting; in these cases, the eyelid will come up when they are alert or are startled. 


Dehydration is another sign of illness. This often occurs when a cat is unable to eat or drink due to pain, especially in the mouth, or more serious illnesses, like kidney failure. 

The pinch test is used to determine if a cat is dehydrated. A healthy cat’s skin will go back to normal when the skin is pinched and released; but a dehydrated cat’s skin will remain ‘tented’:

Elaine demonstrates the pinch test on Molly, a cat suffering from liver problems and asthma.



Teo Heng, a sick cat which was a former resident at Love Kuching. Teo Heng suffered from flu, which caused severe conjunctivitis. (photo: Love Kuching Project)

Conjunctivitis is when the eye is inflamed and produces discharge. The discharge may be clear, or pus-life. It usually indicates cat flu, which can be dangerous for young kittens and senior cats – as well as those who are immunocompromised (like cats with FIV). 

Cats with cat flu will also sneeze and be feverish (warmer than the usual, with a temperature above 39.7 deg C)

Fur loss and itching


Valentine, a stray found at Yale-NUS College. The bald patches on her skin appear to be formed from stress grooming, but fur loss and itching may be caused by other reasons. (photo: NUS Cat Cafe)

Fur loss, presenting itself as bald patches of fur – coupled with scratches on those bald patches – may indicate a skin condition. Most common skin conditions include allergic flea dermatitis and mites; which can be cleared by Revolution – medication that destroys fleas and ear mites.



Ah Niu, a cat who suffered from a spinal fracture. Ah Niu could not walk or rest on his hind legs.

When a cat limps, this usually indicates an injury. It may have had a fall, or it may have had some sort of accident or trauma. Lameness can also come in the form of the cat dragging its hind legs; this may be caused by slight paralysis from a spinal injury.



Charlie, a Hall 11 cat, suffered from gum disease due to its FIV condition.

Drooling isn’t a usual sign of hunger for cats – but it is almost always a sign of gum disease. Gum disease includes decayed teeth, inflamed gums, or ulcerations in the mouth. 

Like humans, cats with bad teeth and gums will also have bad breath. Gum disease can be treated either with medication or surgery – but if the cat is immunocompromised (like Charlie, above), gum disease will be chronic and require long term medication.

Flesh wounds


Ginger, a cat from Hall 9, with a puncture wound.

Flesh wounds can look like open wounds or bleeding puncture wounds, swollen abscesses (looking like they are filled with pus) or large torn skin ‘holes’ in the cat skin, exposing flesh underneath.  A wound that is not tended to can turn into an abscess and if the abscess bursts, the cat’s skin will tear, requiring surgery. As such, it is important that a cat with an open wound be treated for its wound as soon as possible, to prevent the wound from getting infected and turning into a abscess.

Swollen lumps can indicate other illnesses as well, such as tumours and hernias.

Colour of gums

If a cat is close enough to you and allows you to touch its mouth, checking the colour of the gums is also a good indicator of disease. Abnormal gums that look pale, blue or yellow all indicate disease. 

Elaine demonstrates how to check the colour of a cat’s gums with Molly, the same cat as above.

Be vigilant when handling the cat around the mouth, however – if it has gum disease, the cat will feel pain and will retaliate. Be sure to hold it in a firm position – and ensure that it is relatively immobilised.

So, what do you do when a hall cat exhibits one (or more) of these symptoms?

Contact us, here
Email us at cmn@e.ntu.edu.sg

If there’s no time, you can follow the procedures as stated here.

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