Protecting customers with insurance since 2001

Protecting customers with insurance since 2001

Common cat illnesses and diseases

  • 6, Jul 2022
  • Read time: 12 mins

Every now and then, your cat might feel under the weather, or pick up an illness.

This guide takes you through some of the most common cat diseases and illnesses, how to spot them and what to do if you think your cat has one. We’ve also thrown in some typical costs per illness, so you can get an idea of how much you may need to claim for on your pet insurance should your cat fall ill.

Cat receiving vet treatment.

Cat illness symptoms - knowing when your cat is sick

You’ll likely notice if your cat starts to feel unwell. Look out for the following symptoms which might suggest something is wrong:

  • Loss of appetite
  • Change in toilet habits
  • Weight loss
  • Changes in grooming or general behaviour
  • Itching or licking more than usual

What are the common cat illnesses and diseases?


Mostly affecting older cats, hyperthyroidism is a common disease related to the production of thyroid hormones.


If your cat has hyperthyroidism, they may present the following signs:

  • Weight loss
  • Increased appetite
  • Increased thirst
  • Increased urination
  • Vomiting
  • Diarrhoea


The main cause of hyperthyroidism in cats is a non-cancerous tumour (adenoma), which causes the thyroid gland to swell. This can be a result of a dietary deficiency or excess.


There are four types of treatment for hyperthyroidism:

  • Medication – anti-thyroid drugs may be prescribed, and while they will not cure the disease, they will provide short or long-term control
  • Radioactive iodine therapy – this is an injection which destroys the abnormal thyroid tissue, and it usually controls your cats hormone levels within one to two weeks
  • Surgery – removal of the thyroid glands might be necessary. This is a common treatment and can achieve a permanent cure, however signs of hyperthyroidism may return at a later date
  • Diet therapy – limiting the amount of iodine in your cat’s diet. This may not be enough to cure or treat your cat long-term

If you think your cat may be suffering with hyperthyroidism or have a thyroid related disease, seek advice from your vet who can carry out tests.


If your cat is anaemic, it means they have reduced red blood cells and therefore a lack of iron in their blood circulation.


Your cat may show the following signs if they have a lack of iron:

  • Weakness and lethargy
  • Increased heart rate
  • Fast breathing
  • Cravings for unusual foods (soil, cat litter etc)
  • Jaundice/yellowing of the skin
  • Pale gums


There can be many causes of anaemia in cats. The most common are:

  • Loss of blood
  • Infection
  • Eating toxins, such as onions
  • Low phosphate levels in the blood
  • Bone marrow failure
  • Iron deficiency
  • Leukaemia
  • Kidney disease
  • Chronic inflammatory disease


Usually, anaemia is treated with antibiotics or iron supplements, depending on the cause.

If your cat is severely anaemic, they may need to have a blood transfusion.

Your vet will be able to carry out certain tests to determine the underlying cause, and recommend the best course of treatment for your cat.


Common in cats, arthritis causes pain and swelling in joints, and usually presents itself in older cats.


Signs of arthritis can be easy to spot:

  • Difficulty jumping
  • Limping
  • Stiffness in the joints
  • Muscle wastage
  • Increased sleeping
  • Increased grooming or licking
  • Change in behaviour or dislike to being touched


The most common causes of arthritis are:

  • Wear and tear – as your cat ages, they may develop arthritis
  • Genetics – your cat’s breed or genetic make up might make them more prone to developing the disease
  • Injuries and trauma – if your cat has been in an accident or has dislocated or broken a bone before, they may be more likely to go on to develop arthritis


There are various treatments that your vet might recommend for your cat:

  • Anti-inflammatories – usually a daily tablet, these will help to reduce pain and swelling
  • Joint supplements – such as Omega 3 or glucosamine, which may help to slow the arthritis from progressing further
  • Surgery – surgical fusion of the joints might be required if your cat suffers greatly

Depending on the severity of your cat’s arthritis, your vet will be able to recommend the right course of treatment. Seek advice if you’re concerned about your cat’s joints or changes in behaviour.

Kidney disease

Your cat’s kidneys help to keep them healthy by filtering waste from the blood. If they develop kidney disease, the kidneys aren’t able to function this way any more, leading to high levels of waste in the blood.


If your cat is suffering from kidney disease, they may show the following signs:

  • Weakness or lethargy
  • Poor concentration
  • Loss of appetite
  • Swollen feet and ankles
  • Puffy eyes
  • Dry, itchy skin
  • Increased urination, especially at night


Your cat might be more at risk of getting kidney disease if they:

  • Have polycystic kidney disease
  • Have kidney tumours
  • Have a bacterial infection

It might also be that your cat has an underlying cause in their genetic make up, such as:

  • Birth defects
  • Low blood potassium
  • High blood calcium


Depending on the cause of the kidney disease, your vet will be able to recommend the best course of treatment. Usually, it’s managed with medication.

Making sure your cat gets increased fluid intake is important if they suffer from kidney disease. They can become easily dehydrated, so adding water to their food, or being fed tinned or wet foods is usually recommended.

Cat flu

Cat flu is common and can often be treated at home. If your cat is young or old and has other health problems, it can be a dangerous illness.


Similar to human flu, your cat may suffer from the following symptoms:

  • Runny nose and eyes
  • Sore throat
  • Aches and pains
  • High temperature and fever
  • Sneezing
  • Loss of appetite


Feline Herpesvirus (FHV) or Feline Calicivirus (FCV) can cause cat flu. It’s contagious, and can spread between cats from shared bowls and toys.


If you notice any flu-like symptoms in your cat, seek advice from your vet. While there isn’t a cure for the illness, there are medications that might be useful in managing the symptoms.

If your cat requires treatment for cat flu and they are not vaccinated against it, you would not be covered for treatment costs on any MORE THAN pet insurance policies. Other pet insurers also may not cover these costs. 


Cats can develop different types of cancer during their lives, especially as they get older. The most common types are:

  • Lymphoma – cancer of the lymphatic system
  • Squamous cell carcinoma – skin cancer
  • Basal cell tumour – skin cancer
  • Mast cell tumour – skin cancer
  • Mammary carcinoma – cancer of the mammary gland
  • Fibrosarcoma – soft tissue cancer
  • Adenocarcinoma – cancer of the intestines
  • Osteosarcoma – cancer of the bone


Initial signs might be hard to spot as they can be similar to other illnesses and diseases, but look out for:

  • Loss of appetite
  • Lack of energy
  • Lumps on or under the skin
  • Vomiting and diarrhoea
  • Unexplained bleeding or unhealed wounds
  • Changes in toilet habits


Depending on the type of cancer your cat has, your vet will be able to recommend the best course of treatment. Sometimes, your vet might recommend surgery or chemotherapy injections.

If you are concerned about any symptoms in your cat, or changes in behaviour that don’t seem quite right, seek your vet’s advice.


Diabetes is common in cats, and is usually easy to manage once diagnosed. If your cat is old or overweight, they might be more prone to developing diabetes.


The main signs of diabetes in cats can be hard to spot, as they may be similar to symptoms of other illness and diseases. Look out for:

  • Increased thirst
  • Increased appetite
  • Weight loss
  • Increased urination
  • Regular urinary tract infections


Cats can develop diabetes due to being overweight, being old, or if they have a reduced response to insulin.


Your vet may recommend managing the diabetes with medication and diet management.

Some cats can go into diabetic remission with lifestyle changes alone, but if you’re concerned your cat has developed diabetes, seek vet advice.

Urinary infections, conditions and obstructions

If your cat is having problems urinating, they might have a feline lower urinary tract disease (FLUTD).

There are different types of urinary tract infections, such as cat cystitis, or a blocked urethra in male cats.


Common signs that your cat is suffering with a urinary problem are:

  • Urinating in new places, such as around the house
  • Crying when urinating
  • Loss of appetite
  • Increased licking
  • Lethargy
  • Vomiting


Each type of urinary tract conditions in female and male cats can be caused by different things. They can be caused by new illnesses, or a condition that your cat is already suffering from, such as:

  • Stress
  • Bladder infection
  • Bladder stones
  • Hormonal diseases


Your vet will be able to recommend the best course of treatment.

If your cat is suffering with an infection, this may be managed with a course of antibiotics. If there is an obstruction, surgery may be necessary.


Usually, cats will vomit between one and three times a month, and this is seen as normal. If you notice it’s happening more frequently, it could be a sign something isn’t quite right.


Most commonly, cats will meow, retch and heave before vomiting. If it’s a more serious illness, look out for:

  • Loss of appetite
  • Blood in vomit
  • Continuous retching
  • Stomach pain


The most common cause of your cat vomiting is if they have a hairball. This will usually pass, and your cat will feel better.

Vomiting can, however, be a sign of a more serious underlying illness or disease.


There isn’t necessarily a treatment for vomiting in cats, however the following can help them feel more comfortable at home:

  • Make sure they have access to water at all times to stay hydrated
  • Feed them small amounts of plain food, and slowly reintroduce their normal food over time
  • Ensure there’s nothing toxic around the home that can be eaten

Dental problems

Cats can get problems with their teeth at any age. It’s recommended that they have their teeth checked by a vet once a year to prevent dental diseases from developing.


Often, cats won’t show any signs of teeth problems until the pain becomes more severe. If they do show symptoms, these can be:

  • Bad breath
  • Avoiding eating hard food


There are many potential causes of dental issues in cat, such as:

  • Their genetic history
  • Tooth alignment
  • Bacteria in the mouth
  • Plaque and tartar build up


You can help your cat’s dental health at home by feeding them a good diet and keeping up a dental routine.

You can find cat toothpaste and toothbrushes in most pet shops, or your vet can make a recommendation and show you how to clean your cat’s teeth effectively.

If your cat develops a severe dental issue, they may require tooth extraction.

Vet costs of some common cat illnesses

If your cat were to fall ill and need treatment from your vet, this can often be costly. We’ve picked out some of MORE THAN’s top claimed for conditions* in cats to help give you an idea of how much a claim, on average, could cost you:

Hyperthyroidism is MORE THAN’s top claimed for condition in cats.
Average paid out (including excess): £1,082

Kidney disease ranks in MORE THAN’s top 5 claimed for conditions in cats.
Average paid out (including excess): £942

Cat dentistry ranks in MORE THAN’s top 10 claimed for conditions in cats.
Average paid out (including excess): £484

Diabetes ranks in MORE THAN’s top 20 claimed for conditions in cats.
Average paid out (including excess): £1,674

*Based on MORE THAN claims data 1 January 2020 to 21 April 2022.

How common cat diseases affect pet insurance

Knowing the signs and symptoms of common cat illnesses is all part of being a responsible cat owner.

Sometimes it takes a professional to notice something isn’t quite right, so regular vet check-ups are important.

As well as regular check-ups, our vets here at MORE THAN recommend the following:

  • Annual vaccinations up to date
  • Regular parasite control, including flea and deworming
  • Good quality dry food
  • Lots of fresh water bowls around the house
  • Regular grooming, including daily brushing of teeth

If you’re ever worried about your furry friend, contact your vet and they can advise on what to do.

Cover for your cat 

Cat insurance is there for you and your feline family when you need it most. Have added peace of mind knowing that your furry friend could be covered if they fall ill with our three levels of pet insurance cover.

Take a look at our cat insurance and get a quote today

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