Common cat diseases every pet parent should know: signs, causes, and when to see a vet

Please note:
This article is a general guide only and isn’t a substitute for individual vet advice. Every cat is different, and only a vet who has examined your cat can provide personalised advice based on their specific needs. If you’re ever concerned about your cat’s health, contact your vet promptly.

Cats have a remarkable ability to hide pain and discomfort. It’s an instinct inherited from their wild ancestors, where appearing vulnerable could put them at risk. Because of this, it can be easy to miss the signs that your cat may be unwell.

From an unexpected sneeze to changes in appetite or behaviour, recognising possible signs of illness early can help your cat get the care they need sooner.

In this guide, we’ll cover some of the most common cat diseases and health problems, including upper respiratory infections, chronic kidney disease, diabetes, and arthritis. We’ll also take a look at some of the possible causes of these conditions, the signs to look out for as a pet parent, and when it’s time to see your vet.

Table of contents

• Common cat diseases and their signs
• Cat flu (feline upper respiratory infection)
• Feline Immunodeficiency Virus (FIV) and Feline Leukaemia Virus (FeLV)
• Chronic kidney disease
• Feline lower urinary tract disease (FLUTD)
• Diabetes mellitus
• Dental disease and gingivostomatitis
• Ringworm
• Arthritis
• When to see a vet
• How pet insurance can help support you and your cat

Common cat diseases and their signs

Use this table as a guide only. If your cat shows any of these signs, contact your vet for advice.

Condition	Common early signs
Cat flu	Sneezing, discharge from the eyes or nose, fever, mouth ulcers, loss of appetite.
FIV / FeLV	Weight loss, poor coat condition, swollen lymph nodes, recurring infections.
Chronic kidney disease	Increased thirst and urination, weight loss, poor appetite, lethargy.
FLUTD	Straining to urinate, passing small amounts of urine frequently, blood in the urine.
Diabetes mellitus	Drinking more, weight loss despite an increased appetite, urinating more.
Dental disease / gingivostomatitis	Bad breath, drooling, difficulty eating, pawing at the mouth.
Ringworm	Circular patches of hair loss, scaly skin, brittle hair.
Arthritis	Stiffness, reluctance to jump, reduced grooming, changes in usual habits and behaviour.

If you notice any of the signs listed here, contact your vet promptly for advice. The urgency of vet assessment will depend on your cat’s individual circumstances, and your vet can advise how soon they should be seen.

Cat flu (feline upper respiratory infection)

Cat diseases don’t always start with obvious symptoms. Sometimes they begin with an occasional sneeze, watery eyes, or a cat that’s simply not interested in dinner.

Cat flu is a highly contagious upper respiratory illness, most commonly caused by feline herpesvirus (FHV-1) and feline calicivirus (FCV). It spreads through direct contact between cats, as well as indirectly through shared food bowls, bedding, and litter trays.

Common signs include sneezing, coughing, discharge from the eyes and nose, fever, loss of appetite, and ulcers affecting the mouth or eyes. Kittens and older cats are at greater risk of becoming seriously ill. Even after recovery, many cats continue to carry the virus and may shed it again during periods of stress.

Vaccination is the most effective way to help protect cats against cat flu. If your cat is showing signs of illness, keep them separated from other cats and speak to your vet for advice.

Feline Immunodeficiency Virus (FIV) and Feline Leukaemia Virus (FeLV)

FIV and FeLV are both retroviruses belonging to the same family of viruses as human immunodeficiency virus (HIV). In Australia, FIV has been found in around 15% of cats aged two years or older with outdoor access, while FeLV affects approximately 2% of cats. Although they’re often mentioned together, they spread in different ways.

FIV is most commonly transmitted through deep bite wounds, while FeLV can spread through close contact between cats, including through saliva, mutual grooming, and sharing food bowls or litter trays.

Cats with FIV may also develop weight loss, anaemia, and gum inflammation, while FeLV can be associated with tumours of the immune system, poor coat condition, and a rapid decline in overall health.

While there’s currently no cure for either virus, many affected cats can still enjoy a good quality of life with appropriate vet care, good nutrition and regular vet check-ups. Keeping cats safely contained on your property can help reduce the risk of exposure to FIV and FeLV. Vaccines are also available for both diseases, although they’re not recommended for every cat. Speak to your vet about whether this type of vaccination is appropriate for your cat.

Chronic kidney disease

Chronic kidney disease (CKD) is one of the most common diseases affecting older cats, with an estimated 20–50% of cats over 15 years of age experiencing some degree of kidney disease.

The condition develops gradually as the kidneys lose their ability to function normally. Because cats are good at hiding signs of illness, CKD often isn’t recognised until the disease is more advanced.

Early signs can include:

• Increased thirst
• Increased urination
• Weight loss
• Loss of appetite
• Lethargy

Although there’s no cure for chronic kidney disease, early diagnosis can make a significant difference. With an appropriate diet, regular monitoring, and supportive treatment, many cats continue to enjoy a good quality of life for months or even years after diagnosis.

Because CKD is both common and easy to miss in its early stages, regular vet check-ups and appropriate health screening can help detect the condition sooner. Your vet can recommend the most suitable monitoring schedule for your cat based on their age and individual needs.

Feline lower urinary tract disease (FLUTD)

Feline lower urinary tract disease (FLUTD) isn’t a single disease. It’s an umbrella term for a group of conditions that affect a cat’s bladder and urethra. One of the most common causes is feline idiopathic cystitis (FIC), a condition in which stress is thought to play a major role. Other causes include urinary stones.

Signs may include:

• Straining to urinate
• Passing small amounts of urine more frequently
• Blood in the urine
• Urinating outside the litter tray
• Excessive grooming around the belly or genital area

If your cat is straining to urinate but producing little or no urine, particularly if they’re male, treat it as an emergency. A blocked urethra can quickly become life-threatening and requires immediate vet treatment.

While not every case can be prevented, encouraging your cat to drink more water, reducing stress where possible, and helping them maintain a healthy weight may help reduce the risk of some forms of FLUTD.

Diabetes mellitus

Diabetes mellitus is one of the most common disorders affecting cats. It develops when the body doesn’t produce enough insulin, or doesn’t respond to insulin properly, causing blood glucose levels to become too high. The condition is more commonly seen in middle-aged, overweight, neutered and male cats.

Common signs include:

• Drinking more than usual
• Urinating more often
• Losing weight despite having a bigger appetite
• Poor coat condition

Without treatment, diabetes can progress to diabetic ketoacidosis, which can cause vomiting, lethargy, and collapse. This is a medical emergency which requires immediate vet attention.

Many diabetic cats can continue to enjoy a good quality of life with appropriate treatment. Depending on the individual cat’s circumstances, this may include insulin therapy, oral medication, dietary changes, and regular monitoring.

Dental disease and gingivostomatitis

Dental disease is one of the most common cat illnesses out there. Plaque begins building up on your cat’s teeth every day and can harden into tartar within just a few days. Without treatment, this can lead to gingivitis (inflamed gums) and eventually, periodontal disease.

Some cats also develop feline chronic gingivostomatitis, a severe and painful inflammation affecting the gums and mouth, which may be associated with infections, dental disease, or an overactive immune response.

Signs often include:

• Bad breath
• Drooling
• Reduced appetite
• Difficulty eating hard food
• Pawing at the mouth

Good dental hygiene, including regular tooth brushing at home, is an important part of helping to prevent dental disease and maintain your cat’s oral health. Regular vet check-ups can also help identify dental and oral health problems early. Your vet can advise whether further assessment or professional dental treatment is needed for your cat.

To learn more about caring for your cat’s teeth, please refer to our cat dental care guide.

Ringworm

Despite its name, ringworm isn’t a worm. It’s a fungal infection affecting the skin and hair, and it’s zoonotic, meaning it can spread from cats to people. Young kittens, older cats, long-haired cats and cats who are unwell are generally at greater risk. Ringworm also spreads easily in environments where cats live closely together.

Typical signs include:

• Circular patches of hair loss
• Scaly skin
• Brittle hair
• A reddened ‘ring’ on hairless areas

Some cats carry the infection without showing any obvious symptoms, which means it can sometimes spread before it’s recognised. If you suspect your cat may have ringworm, contact your vet for advice.

For more information on ringworm in pets, you can read our blog here.

Arthritis

Arthritis (osteoarthritis) is more common in cats than many pet parents realise. While age is one of the biggest risk factors, genetics, breed, and old injuries can all play a role.

Common signs of arthritis in cats include:

• Reluctance to jump or climb
• Stiffness, especially after resting
• Reduced interest in play or activity
• Reduced grooming
• Irritability when touched
• Difficulty getting in and out of the litter tray

These changes are often mistaken for normal signs of ageing, but arthritis is a painful condition that can affect a cat’s quality of life. If you notice any of these signs, contact your vet who can recommend the most appropriate approach based on your cat’s individual needs.

If your cat has arthritis, there are several ways you can support them at home. Providing ramps or easy access to favourite resting spots, adding an extra layer of soft bedding, and using a low-sided litter tray can all help make daily activities more comfortable.

When to see a vet

Many common cat illnesses are easier to manage when they’re identified early. Regular vet check-ups and paying attention to changes in your cat’s behaviour and daily habits can help identify potential health problems sooner.

Contact your vet promptly if your cat:

• Is straining to urinate but passing little or no urine
• Is having difficulty breathing or breathing rapidly
• Has collapsed, had a seizure, or can’t stand
• Has suddenly stopped eating or drinking
• Is vomiting repeatedly or has ongoing diarrhoea
• Seems disorientated, very weak, or appears to be in pain
• Is showing any other concerning changes in behaviour, habits, or overall health

The urgency of vet assessment will depend on your cat’s individual circumstances and the signs they’re showing. Your vet will determine how soon your cat needs to be seen and advise on the most appropriate next steps.

How pet insurance can help support you and your cat

Even generally healthy cats can develop illnesses or injuries that lead to unexpected vet expenses. From infectious diseases such as cat flu to the ongoing management of conditions like diabetes or chronic kidney disease, treatment costs can add up over time.

With RSPCA Pet Insurance, eligible health conditions are covered, giving you the confidence to seek vet care when your cat needs it. And with every policy contributing to vital RSPCA animal welfare initiatives, including rescue, rehab, and rehoming efforts, it’s protection with purpose. For your own cat and thousands of others across Australia.

To learn more about how RSPCA Pet Insurance could support you and your cat with customisable cover, click here. Or, if you’re ready to take the next step, you can fetch a commitment-free pet insurance quote online today.

Disclaimer

As with any insurance, terms, conditions, and exclusions apply. Please read the Product Disclosure Statement to make sure this cover suits your needs.

 

References 

[1] RSPCA Australia. What is cat flu and how is it managed? RSPCA Knowledgebase. Available from: https://kb.rspca.org.au/categories/companion-animals/cats/health-issues/what-is-cat-flu-and-how-is-it-managed

[2] RSPCA Australia. What are Feline Immunodeficiency Virus (FIV) and Feline Leukaemia Virus (FeLV)? RSPCA Knowledgebase. Available from: https://kb.rspca.org.au/categories/companion-animals/cats/health-issues/what-are-feline-immunodeficiency-virus-fiv-and-feline-leukaemia-virus-felv

[3] International Cat Care. Chronic kidney disease (CKD) in cats. Available from: https://icatcare.org/articles/chronic-kidney-disease-ckd-in-cats

[4] International Cat Care. Feline Lower Urinary Tract Disease. Available from: https://icatcare.org/articles/feline-lower-urinary-tract-disease

[5] International Cat Care. Diabetes mellitus in cats. Available from: https://icatcare.org/articles/diabetes-mellitus-in-cats

[6] RSPCA Australia. What do I need to know about gum and mouth inflammation (gingivostomatitis) in cats? RSPCA Knowledgebase. Available from: https://kb.rspca.org.au/categories/companion-animals/cats/health-issues/what-do-i-need-to-know-about-gum-and-mouth-inflammation-gingivostomatitis-in-cats

[7] RSPCA Australia. What is ringworm and how do I know if my companion animal has it? RSPCA Knowledgebase. Available from: https://kb.rspca.org.au/categories/companion-animals/cats/health-issues/what-is-ringworm-and-how-do-i-know-if-my-companion-animal-has-it

[8] RSPCA Australia. I think my cat has arthritis, what should I do? RSPCA Knowledgebase. Available from: https://kb.rspca.org.au/categories/companion-animals/cats/health-issues/i-think-my-cat-has-arthritis-what-should-i-do