Common Cat Illnesses

There are a number of common complaints that could affect any cat. When they are ill for any reason cats often become lethargic and withdrawn. Contact your vet if you have any concerns.

Alterations in Food Intake

Sudden changes in your cat’s behaviour can be a sign of illness, and changes in eating behaviour are some of the most obvious signs of a problem. Although there can be innocent reasons for your cat not eating (including hunting or very hot weather) a reduced appetite can also indicate underlying disease. If these issues accompany severe weight loss it’s best to contact your vet.

In contrast, you should also watch out for signs of excessive weight gain and obesity. In healthy cats you should be able to just feel your cat’s ribs. If you cannot then your cat is probably overweight and you should seek veterinary advice. Do not put your cat on a weight reduction diet without such advice because sudden restrictions in food intake can lead to severe liver problems in cats.

Alterations in Thirst

An increase in drinking or urinating can be a sign of conditions such as diabetes or kidney problems. If you notice a change in water consumption, or if the litter tray is unusually sodden, arrange a check-up at your vets. Your vet may ask you exactly how much your cat is drinking each day. Try to measure it’s water intake over a 24 hour period before your appointment.


The occasional vomiting of fur-balls or grass may be normal if in some cats. However, if the frequency increases, or if your cat vomits food or blood, then this is a serious concern. Vomiting accompanied by lethargy, depression, diarrhoea or loss of appetite indicates an underlying problem and veterinary attention should be sought.

Issues with Urination or Defecation

If your cat is using the litter tray more frequently than normal or if the faeces looks unusually hard, soft or watery this may be a sign of illness For instance, if your cat’s faeces are hard or full of hair or if you see your cat straining to pass faeces, or if your cat has not passed faeces for several days it would be best to contact your veterinary surgeon to check for constipation. There may be a simple reason for it, such as a change in diet, but if you’re unsure always seek help. In addition; if your cat has diarrhoea, unusually soft stools, blood or mucous in it’s stools contact your vet for advice.

Conditions affecting you cat’s lower urinary tract (bladder and urethra) can cause frequent visits to the litter tray, or even squatting to urinate and remaining in this position without producing urine (or producing only a small amount). Other signs to watch for are crying when in the litter tray, or production of blood-tinged urine. It is particularly important to contact your vet immediately on noticing these signs if you own a male cat, as being unable to urinate can be life-threatening.

Problems with Movement

If your cat is limping, becoming slow or is stiff getting up or lying down, this may indicate a bone or joint problem, so let your vet know. Equally, if your cat becomes unusually hyperactive, scatty or uncomfortable with being handled, even to the point of aggression, it’s worth checking with your vet as changes like these may indicate an underlying health problem.

Skin complaints

Skin and coat condition is a good indicator of health. Skin should be smooth and pink or black and the coat should be smooth and shiny. Scratching or over-grooming, scabs on the skin and pulling out fur can indicate skin disease. Scratching accompanied by small black dots in the coat- especially over the back and above the tail base could suggest fleas. Any brownish discharge or redness in the ears should be investigated by your vet.

Odd behaviour

One of the most common signs that your cat is feeling unwell is a sudden behaviour change. If your cat becomes withdrawn, or resents being picked up, or exhibits any other odd behaviour then consult your vet.

If your cat has any of the symptoms listed above, or if you are worried about the health of your cat, you would be best advised to visit your vet in the first instance. Owners of older cats are advised to take their cats for a check-up every three to six months and adult cats should see their vet at least annually when they have their booster vaccinations. Whilst books and websites can provide valuable information, do not rely on them for a diagnosis.