13 Common Cat Diseases & Symptoms Every Owner Must Know

Cats are masters at hiding pain. Their wild ancestors couldn't afford to look weak, so even today, your house cat will quietly suffer through symptoms you might miss until it's serious. Knowing the common cat diseases and their early warning signs can be the difference between a quick vet visit and an emergency hospital stay. This guide walks you through the 13 most frequent feline health problems, the subtle signs to watch for, and when to call the vet.

What Are the Most Common Cat Diseases?

The most common cat diseases worldwide are:

1. Feline Lower Urinary Tract Disease (FLUTD)
2. Chronic Kidney Disease (CKD)
3. Hyperthyroidism
4. Diabetes Mellitus
5. Dental Disease
6. Upper Respiratory Infection (URI)
7. Feline Leukemia Virus (FeLV)
8. Feline Immunodeficiency Virus (FIV)
9. Feline Infectious Peritonitis (FIP)
10. Inflammatory Bowel Disease (IBD)
11. Heartworm Disease
12. Cancer (especially Lymphoma)
13. Parasites (fleas, worms, ear mites)

Quick Symptom-to-Disease Reference Table

Save this table. It works as a reverse lookup when something feels off, but you can't yet name the problem.

Early Warning Signs of a Sick Cat

Cats hide illness, so the first signs are often behavioural rather than physical.

Behavioural Red Flags

• Hiding under furniture or in unusual spots
• Reduced grooming or a greasy, matted coat
• Loss of interest in play or affection
• Litter box changes (more visits, fewer visits, or accidents)
• Hissing or flinching when touched

Physical Symptoms

• Weight loss or sudden weight gain
• Excessive thirst
• Vomiting more than once a week
• Limping or stiff movement
• Cloudy eyes, runny nose, or bad breath

13 Common Cat Diseases and Their Symptoms

1. Feline Lower Urinary Tract Disease (FLUTD)

A cluster of conditions affecting the bladder and urethra. Symptoms include straining, blood in urine, frequent small urinations, and crying in the litter box. A fully blocked male cat is a life-threatening emergency.

2. Chronic Kidney Disease (CKD)

Common in older cats. Research from Cornell Feline Health Center suggests roughly 30 to 40 percent of cats over age 10 develop some form of kidney disease. Watch for increased thirst, weight loss, poor coat, and bad breath.

3. Hyperthyroidism

An overactive thyroid gland, mostly in cats above 10. Signs include a huge appetite paired with weight loss, restlessness, vomiting, and a fast heart rate.

4. Diabetes Mellitus

Often linked to obesity. Look for excessive thirst, frequent urination, weight loss despite eating well, and weakness in the back legs.

5. Dental Disease (Periodontitis)

The American Veterinary Medical Association (AVMA) reports that the majority of cats over age 4 show signs of dental disease. Symptoms include bad breath, drooling, dropping food, and pawing at the mouth.

6. Upper Respiratory Infection (URI)

Like a cat version of the common cold. Sneezing, watery eyes, nasal discharge, and reduced appetite. Very common in shelter and multi-cat homes.

7. Feline Leukemia Virus (FeLV)

A serious viral disease spreads through saliva and shared bowls. The Advisory Board on Cat Diseases (ABCD) estimates global FeLV infection rates between 2 and 5 percent. Symptoms: pale gums, weight loss, recurring infections, and fatigue.

8. Feline Immunodeficiency Virus (FIV)

The feline equivalent of HIV, mostly spread through deep bite wounds in outdoor fights. FIV cats can live years symptom-free before immunity drops and secondary infections appear.

9. Feline Infectious Peritonitis (FIP)

Caused by a mutated coronavirus. Once almost always fatal, but newer antiviral treatments are improving outcomes. Look for fluid build-up in the belly, fever that won't go away, lethargy, and weight loss.

10. Inflammatory Bowel Disease (IBD)

Chronic gut inflammation. Symptoms include long-term vomiting, diarrhoea, and gradual weight loss.

11. Heartworm Disease

Less common in cats than in dogs, but harder to treat. Watch for coughing, asthma-like wheezing, vomiting, and sudden collapse.

12. Cancer (Lymphoma and Others)

Lymphoma is the most common feline cancer, often linked to FeLV in younger cats. Signs vary widely: lumps, weight loss, vomiting, or trouble breathing.

13. Parasites (Fleas, Worms, Ear Mites)

Itching, scratching, dark debris in ears, visible worms in stool, or a bloated belly in kittens. Easy to prevent, easy to miss.

Indoor vs Outdoor Cats: Disease Risk Differences

Outdoor cats face higher risk of:

• FIV and FeLV from fights and shared territory
• Parasites and tick-borne illness
• Trauma from cars, predators, and falls

Indoor cats face higher risk of:

• Obesity and diabetes from low activity
• FLUTD linked to stress and dry-food diets
• Dental disease from soft diets
• Behavioural stress and overgrooming

A short veterinary survey published by International Cat Care (iCatCare) notes that indoor-only cats live longer on average but develop more lifestyle-linked illnesses. The fix is enrichment: tall scratchers, food puzzles, window perches, and daily play.

Kitten, Adult & Senior Cat Disease Profiles

• Kittens (0 to 1 year): Upper respiratory infections, intestinal parasites, FIP, fading kitten syndrome
• Adults (1 to 9 years): Dental disease, FLUTD, obesity, diabetes, IBD
• Seniors (10 plus): Chronic kidney disease, hyperthyroidism, cancer, arthritis

Adjust your vet schedule with age. Adult cats need yearly check-ups. Seniors need check-ups every six months, including blood and urine tests.

Diseases Cats Can Pass to Humans (Zoonotic)

Some feline illnesses can spread to people, especially children, pregnant women, and anyone with a weak immune system. The most common ones are:

• Toxoplasmosis (from infected cat faeces)
• Ringworm (a fungal skin infection)
• Cat-Scratch Disease (caused by Bartonella bacteria)
• Rabies (rare in vaccinated indoor cats but always serious)

Wash hands after cleaning the litter box, deworm regularly, and keep vaccinations current.

When to Call Your Vet vs Emergency Vet

Book a regular vet appointment within 24 to 48 hours if your cat:

• Has been off food for more than a day
• Is vomiting more than twice in a day
• Is limping or unusually quiet for two days
• Has new lumps or sudden weight loss

When in doubt, call. Most clinics will triage over the phone for free.

How to Prevent Common Cat Diseases

• Annual vet check-ups (every 6 months for seniors)
• Core vaccinations and parasite prevention
• Fresh water in clean bowls daily
• High-quality, balanced food and weight control
• Daily play and mental enrichment
• Regular tooth brushing or dental treats
• Keep your cat indoors or supervised outdoors

A consistent routine prevents most of the conditions on this list.

FAQ

Conclusion

Cats rely on you to read the signs they cannot speak. Most common cat diseases are far easier to treat when caught early, and many can be prevented with simple routines: yearly check-ups, dental care, parasite prevention, fresh water, and daily play. Trust your gut. If something seems off about your cat for more than a day or two, that quiet hunch is usually right.