Common Signs of Illness in Cats

Cats are well known for hiding discomfort, which can make it difficult to spot when something is wrong. In many cases, the early signs of illness are subtle and easy to miss. A cat may simply seem quieter than usual, eat a little less, or spend more time hiding. Because cats often mask pain and illness until they feel quite unwell, noticing small changes early can make a real difference.

For UK cat owners, understanding the common signs of illness can help you decide when to monitor your cat at home and when to contact your veterinary surgeon. If you are ever unsure, it is always safest to seek professional advice.

This article is intended for general guidance only and should not replace professional veterinary advice. If your pet is unwell or showing concerning symptoms, please contact your veterinary surgeon.

Why early signs matter in cats

Cats can become poorly quite quickly, and some conditions are much easier to manage when caught early. Changes in appetite, litter tray habits, behaviour, grooming, or energy levels may all be clues that your cat needs veterinary attention.

It can also be helpful to keep up with routine preventative care, including parasite control, regular weight checks, and timely veterinary reviews. If you are looking for everyday healthcare products, you can browse our cat collection, including support for common cat health needs.

Common signs your cat may be unwell

1. Changes in appetite or drinking

A healthy cat is usually fairly consistent in its eating and drinking habits. If your cat suddenly stops eating, eats much less than normal, or seems unusually thirsty, this may suggest an underlying problem.

Loss of appetite can be linked to dental pain, digestive upset, infection, kidney disease, stress, or other illnesses. Drinking more than usual may be seen with conditions such as diabetes, kidney problems, or an overactive thyroid gland.

• Refusing food for more than 24 hours
• Eating much less than normal
• Drinking noticeably more or less
• Difficulty chewing or dropping food

If your cat has ongoing digestive issues, your veterinary surgeon may recommend treatment or supportive products. We also stock a range of cat digestion products where appropriate.

2. Vomiting or diarrhoea

The occasional hairball may not be unusual, but frequent vomiting or diarrhoea should not be ignored. These signs can happen with dietary upset, parasites, infection, inflammatory bowel problems, toxin exposure, or more serious disease.

Kittens, elderly cats, and cats with ongoing health conditions can become dehydrated more quickly, so it is especially important to monitor them closely.

• Repeated vomiting
• Diarrhoea lasting more than a day
• Blood in vomit or stools
• Lethargy alongside stomach upset

3. Weight loss or weight gain

Gradual weight changes can be easy to miss, especially in long-haired cats. Unexplained weight loss may point to problems such as dental disease, digestive illness, diabetes, kidney disease, or thyroid disease. Weight gain can also affect your cat’s health and may increase the risk of arthritis, diabetes, and reduced mobility.

Regularly checking your cat’s body condition at home can help you spot changes sooner.

4. Changes in litter tray habits

Litter tray changes are an important warning sign in cats. Straining to urinate, passing urine more often, urinating outside the tray, constipation, or diarrhoea may all indicate illness.

Urinary problems in cats can become serious very quickly, especially in male cats. A cat that is repeatedly going in and out of the litter tray, straining, crying, or producing little to no urine needs urgent veterinary attention.

• Straining to urinate or defecate
• Blood in urine
• Urinating outside the litter tray
• Passing very small amounts of urine

If your cat is prone to urinary issues, your vet may advise a specific diet, supplements, or prescription treatment. You can find relevant support in our cat urinary products collection, but always check with your veterinary surgeon first if symptoms are new or worsening.

5. Tiredness, weakness, or hiding away

Many cats enjoy a quiet life, so it can sometimes be tricky to tell the difference between normal rest and unusual lethargy. If your cat seems much less active, is reluctant to jump, hides more than usual, or seems weak, this may suggest pain or illness.

Some cats become withdrawn when they are not feeling well, while others may become clingier than usual. Any clear change in your cat’s normal behaviour is worth paying attention to.

6. Breathing changes

Breathing should be calm and quiet in a relaxed cat. Fast breathing, noisy breathing, wheezing, coughing, or breathing with an open mouth are all signs that need prompt attention.

Breathing difficulties can be linked to asthma, heart disease, infection, pain, or other serious conditions. Open-mouth breathing in a cat is especially concerning and should be treated as urgent.

• Rapid breathing at rest
• Wheezing or noisy breathing
• Coughing
• Open-mouth breathing

For cats already diagnosed with ongoing respiratory conditions, your vet may prescribe treatment from our cat respiratory products range.

7. Changes in grooming or coat condition

A healthy cat usually keeps its coat clean and well groomed. A coat that becomes greasy, matted, flaky, or unkempt may suggest that your cat is unwell, in pain, overweight, or struggling with mobility.

Overgrooming can also be a sign of skin irritation, allergies, parasites, pain, or stress. Bald patches, scabs, dandruff, or frequent scratching should be checked by a veterinary professional.

Routine flea prevention plays an important role in skin health. You can browse our cat flea, tick and worming products if your cat needs regular parasite protection.

8. Eye, ear, or nose problems

Discharge from the eyes or nose, redness, swelling, squinting, head shaking, or a bad smell from the ears may all point to infection, irritation, injury, or allergy.

Cats with eye problems can deteriorate quickly, so it is best not to delay seeking advice if your cat seems uncomfortable or keeps one eye closed.

Where suitable and under veterinary guidance, we offer cat eye products and cat ear products for common care needs.

9. Bad breath or mouth discomfort

Bad breath is often dismissed, but in cats it can be a sign of dental disease, mouth inflammation, or other health problems. You may also notice drooling, reluctance to eat, pawing at the mouth, or favouring one side when chewing.

Dental problems can be painful and may affect your cat’s appetite and wellbeing. If you think your cat may have mouth pain, it is worth arranging a veterinary check.

For ongoing home care after professional advice, you can explore our cat dental products.

Behaviour changes can be a sign of illness

Behaviour changes are sometimes the first sign that a cat is not feeling well. A usually friendly cat may become irritable, while an independent cat may suddenly become very clingy. Stress can play a role, but pain and illness should always be considered too.

• Hiding more than usual
• Reduced interaction with people
• Sudden aggression or irritability
• Confusion or disorientation
• Changes in sleep patterns

If your cat is prone to stress-related behaviours, products such as pheromone diffusers may be helpful alongside good environmental management. You can view our cat pheromone products and cat behaviour products for additional support.

When to contact a veterinary surgeon urgently

Some symptoms should never be monitored at home for long. Contact your veterinary surgeon promptly, or seek urgent help, if your cat has any of the following:

• Difficulty breathing or open-mouth breathing
• Collapse, severe weakness, or unresponsiveness
• Repeated vomiting or severe diarrhoea
• Straining to urinate or inability to pass urine
• Seizures
• Severe pain, distress, or sudden swelling
• Suspected poisoning
• A wound, bite, or injury

If your vet prescribes treatment, we can help you order it safely and conveniently through our prescription medicine ordering page. You can also read our prescription FAQs for more information.

How to monitor your cat at home

You know your cat best, so trust your instincts if something seems off. Keeping a simple note of symptoms can be helpful if you need to speak to your veterinary practice.

• Track eating and drinking habits
• Monitor litter tray use
• Check for vomiting, diarrhoea, or coughing
• Look for changes in weight or body shape
• Notice any changes in mood, grooming, or activity

Try not to give human medication or leftover pet medication unless your veterinary surgeon has specifically advised it. Responsible use of medicines is important, as some products can be dangerous if given incorrectly.

Supporting your cat’s health

Preventative care can help reduce the risk of some common health issues and make problems easier to spot early. Useful steps include:

• Regular veterinary check-ups
• Routine flea and worm treatment
• Maintaining a healthy body weight
• Feeding a balanced diet
• Keeping vaccinations up to date
• Monitoring dental health

If you are looking for general cat healthcare products, nutritional support, or prescribed medication once approved by your vet, you can explore our cat supplements, cat prescription products, and wider Vetscriptions range.

Conclusion

Spotting illness in cats is not always straightforward, but small changes can be significant. Paying attention to appetite, behaviour, breathing, litter tray habits, grooming, and energy levels can help you recognise when your cat may need veterinary care.

In general, if your cat is acting out of character, seems uncomfortable, or has symptoms that persist or worsen, it is best to contact your veterinary surgeon. Early advice can provide reassurance and, in some cases, help your cat get the treatment they need sooner.

At Vetscriptions, we are here to support UK pet owners with trusted information and access to genuine pet medicines and healthcare products. You can browse our cat healthcare range, learn more about us, or get in touch if you need help with ordering prescribed medication responsibly.

If you are concerned about your cat’s health, please speak to your veterinary surgeon for personalised advice.