A Practical Guide to Common Cat Diseases

In this guide

Learning to recognise and respond to illness in your cat is one of the best things you can do to help them live a long, comfortable life. Contrary to popular belief, domestic cats aren't walking disease factories — there genuinely aren't many serious illnesses you can catch from a pet cat, which is one reason they make such good companions. Even so, there are conditions worth understanding, both the ones that affect cats themselves and the small handful that can pass between cats and their owners.

Setting the Record Straight

A few cat diseases have names that sound alarmingly close to serious human conditions, which has led to some persistent myths. Feline leukaemia virus (FeLV) causes leukaemia in cats only — it cannot infect people and can't survive in the human body. Feline immunodeficiency virus (FIV) is sometimes nicknamed "feline AIDS" because it belongs to the same viral family as HIV, but that's where the similarity ends: FIV cannot infect humans or cause human AIDS. Likewise, the viruses behind a cat's sneezing and runny eyes don't cross over to humans either. Cats can develop many of the same diseases people do — diabetes, arthritis, heart disease, cancer — but none of these are contagious between species.

That said, a small number of conditions genuinely can pass from cats to their owners:

• Fleas feed on blood and, while they prefer the warmer body temperature of cats and dogs, a hungry flea won't say no to a human meal either. The main risk is itching and irritation rather than disease.
• Ticks are similarly opportunistic and can carry Rocky Mountain spotted fever or Lyme disease. Remove them promptly with tweezers, gripping as close to the skin as possible and pulling straight out with steady pressure — never use heat or a lit match. Drop the tick in rubbing alcohol afterwards and dab the bite with antiseptic.
• Worms can be picked up through careless handling of litter or contaminated soil, and children are especially at risk. They're often hard to spot, so a vet check of your cat's stool is the most reliable way to catch an infestation, and treatment is quick once diagnosed.
• Ringworm isn't a worm at all — it's a fungus causing bald, scaly, ring-edged patches. Cats can carry and spread it without showing symptoms themselves, so if it turns up, expect to treat the whole household, cats included, since spores can linger for months.
• Rabies is fatal and, once symptoms appear, essentially untreatable, which makes prevention through vaccination essential, even for indoor cats. It spreads through bites and scratches from infected animals, so any bite from an unfamiliar animal warrants medical attention.
• Cat scratch disease is a real, medically recognised condition. Bites in particular need prompt washing and, often, a call to your doctor — you may need antibiotics or a tetanus booster.
• Toxoplasmosis is caused by a parasite passed in infected cats' stool. Most people who contract it show no symptoms, though it poses real risk to pregnant women and anyone with a compromised immune system. Most human infections actually come from gardening in contaminated soil or eating undercooked meat rather than from litter trays, and roughly seven in ten adults have already been exposed and carry immunity.

Spotting the Early Warning Signs

Cats can't tell you when something's wrong, and their limited range of facial expressions makes it easy to miss the subtle cues. Watch for:

Behaviour changes. A friendly cat turning moody or touchy, or a shy cat suddenly becoming clingy, can both signal something's off. New habits, like drinking from the tap for the first time or scratching at the ears more than usual, are also worth noting. Increased thirst in particular can point to kidney problems or early diabetes.

Appearance changes. Sudden weight gain or loss (assuming diet hasn't changed), a duller coat, thinning fur, or hair that feels coarse or brittle are all worth flagging with your vet — though bear in mind some of this is simply a natural part of ageing.

Appetite and toileting changes. Cats are genuinely fussy, but a sudden loss of interest in food they've always eaten, or the opposite — ravenous new hunger — can both indicate illness. Pay attention to litter tray contents too: noticeable changes in urine or stool volume, blood, mucus, a strong odour, or a previously reliable cat suddenly missing the tray are all signals worth investigating.

These changes often creep up gradually, which is exactly why they're easy to miss. A cat developing diabetes, for example, might take weeks to go from one extra trip to the water bowl to several — a shift that's nearly impossible to notice day by day. Training yourself to observe your cat's everyday habits pays off enormously here.

When to Call the Vet Immediately

Some situations call for urgent veterinary attention, no hesitation required:

• Heavy bleeding from any part of the body
• Suspected fractures or dislocations
• Loss of consciousness
• A fever above 102°F (a cat's normal temperature runs slightly warmer than ours, but sustained fever above this needs attention)
• Difficulty breathing, swallowing, standing or walking, or an uncoordinated gait
• Straining or crying in the litter tray, especially while urinating
• Convulsions, electrocution or drowning
• Any blunt trauma — falls, being hit by a car, getting caught in doors — even without obvious injury, since internal damage isn't always visible

Beyond emergencies, any symptom that lingers more than 48 hours, or that worsens at any point, deserves a call to your vet. Don't wait out the full 48 hours if a symptom is interfering with breathing, eating, drinking or toileting — call straight away.

Asthma

Feline asthma is a chronic breathing condition, not contagious, that causes bouts of laboured, wheezy breathing. During an attack you may notice rapid, open-mouthed breathing and, in severe cases, a bluish tinge to the gums and tongue — never attempt CPR on a cat mid-attack. Asthma often develops from allergic bronchitis, an inflammation triggered by inhaled irritants such as dust, litter particles or smoke, and left untreated it can cause lasting lung damage.

What helps: Minimising stress (yes, cats get stressed too — often from household change of any kind, positive or negative), keeping the air free of scented sprays, smoke, and chemical fumes from paints or cleaners, using unscented, low-dust litter, running a humidifier to keep airways moist, and maintaining a healthy weight through balanced diet and regular, gentle activity.

When to call the vet: Any full-blown attack is an emergency. Milder signs — noisy breathing, occasional wheeze, laboured breathing after exertion — should still prompt a vet visit soon, since early treatment can prevent things escalating.

Cystitis and Urinary Tract Disease

Bladder inflammation, often part of a broader condition called feline lower urinary tract disease (FLUTD), shows up as bloody urine, frequent small urinations, litter tray accidents, spraying, excessive licking, straining, and abdominal tenderness. Urine pH plays a big role here — alkaline urine encourages crystal formation, which can irritate the bladder lining or, in male cats, cause a dangerous blockage.

What helps: Diet matters enormously — your vet may recommend a prescription food formulated to manage urinary pH. Constant access to fresh water is essential, since concentrated urine irritates a bladder that's already sensitive; wet food helps boost fluid intake too. Minimising stress and keeping the litter tray scrupulously clean also reduce flare-up risk.

Diabetes

Diabetes results from insufficient insulin production, leading to excessive thirst, frequent urination, elevated blood sugar, increased appetite and slow wound healing. Left untreated, affected cats lose weight despite eating more, and eventually become lethargic, with vomiting, diarrhoea and weakness following. It's largely a disease of older cats and is strongly linked to obesity — cats over 15 pounds face roughly double the risk.

What helps: Keeping weight under control through portion control and regular activity, feeding a high-fibre diet in smaller, more frequent meals to keep blood sugar steady, and staying scrupulously consistent with feeding and medication timing. Watch for hypoglycaemia in cats on insulin — shaking, disorientation, drooling, staggering or seizures — and keep an emergency sugar source like honey on hand, rubbing a little on the gums and calling the vet immediately if it occurs.

Feline Immunodeficiency Virus, Leukaemia and FIP

FIV, FeLV and FIP are three separate, serious viral diseases, each contagious only between cats. FIV spreads mainly through bites, making unneutered males who roam and fight the most at-risk group. FeLV and FIP typically spread through prolonged close contact — shared grooming, food, water or litter areas — and can also pass from mother to kittens.

What helps: Testing any new cat before introducing them to your household, keeping cats indoors to limit exposure, and vaccinating where available (vaccines exist for FeLV and FIP). A positive result isn't necessarily the end — with good care, infected cats can live for years. Treatment generally focuses on managing symptoms and secondary complications as they arise.

When to call the vet: Annual checkups matter enormously here, since early signs are often too subtle to catch at home. Report any abdominal swelling, persistent low-grade illness, new lumps, or bites from cats of unknown status.

Kidney Disease

The kidneys filter waste from the blood, and damage from age, injury or illness can quietly erode their function — often with no visible signs until real damage has occurred. As things progress, a cat drinks and urinates more to compensate; eventually, waste builds up in the body, causing vomiting, appetite loss, weight loss and a telltale ammonia smell on the breath. By the time symptoms are obvious, a cat has often already lost a majority of kidney function.

What helps: Watching for increased thirst, appetite loss, listlessness, changes in urination, or a hunched, sore posture, and getting to the vet promptly for blood testing and diagnosis. Once diagnosed, a strict prescribed diet and medication regime, followed carefully, can meaningfully extend quality of life.

Liver Disease

The liver filters toxins from the blood, and damage can stem from infections, poisoning, birth defects or other underlying illness. Because symptoms overlap heavily with other conditions — appetite loss, vomiting, diarrhoea, fever, weight loss, dehydration — liver problems can be tricky to pin down. Jaundice, a yellowish tinge to the eyes, skin or under the tongue, is the clearest giveaway.

What helps: Catching problems early gives the best chance of reversing damage, so don't delay a vet visit for a cat that isn't improving. Once diagnosed, sticking rigidly to prescribed diet and medication is essential for recovery.

Tooth and Gum Disease

Plaque builds up from food and saliva, and can harden into tartar, leading to gum inflammation and eventually tooth loss if ignored. Actual cavities are rare in cats, but pitting and other damage can still occur.

What helps: Brushing a few times a week, using gauze or a soft cloth if a proper toothbrush isn't tolerated, goes a long way toward controlling plaque. Dry food and dental chews can help too. Tartar — greyish or brown deposits that won't budge with brushing — needs professional removal by your vet, as does any gum bleeding, swelling, or broken tooth with exposed pulp.

Upper Respiratory Disease

The feline equivalent of a cold — sneezing, runny eyes and nose, sometimes fever — is usually caused by one of a few well-understood, vaccine-preventable viruses. Most cases clear up within a couple of weeks, though severe infections or cats with weakened immunity may take longer. As the infection worsens, discharge can thicken and turn cloudy, the eyes may become inflamed, and mouth ulcers can appear; in advanced, untreated cases, pneumonia can develop and is sometimes fatal.

What helps: Keeping vaccinations current (even indoor cats need this, since the virus travels through the air), not waiting out a cold that isn't clearing on its own, and isolating an infected cat from others in the household, with thorough handwashing after contact.

Cats, like people, are vulnerable to illness, and staying alert to changes in their behaviour, appearance and habits is the best tool you have for catching problems early. When in doubt, a call to your vet is always worth making.

Article content © Ravi Teja. All rights reserved.