Cat Illnesses – most common

I list the most common cat illnesses. There is a concise summary against each illness with links to more information. I have illustrated each section with a cat who had the illness. Photo credits. There are no hard and fast lists on what are the most common feline illnesses. The list below is reliable. However,  a survey of Banfield pet hospitals (USA 2011) came up with a top 5 of: dental tartar (gum disease), fleas, overweight, tapeworms, and cystitis (bladder infections – UTIs). Being overweight is arguably not a disease but it does cause disease. Neither are fleas a disease but again they are a source of disease.

cat with diarrhea

Note: Diarrhea is a symptom not a disease. One of the most common cat illnesses.
Cause: Overfeeding; eating: dead animals, garbage, decayed food, rich food, indigestible objects; intestinal parasites, toxic substances, cows milk, certain foods, stress, excitement, non-routine water, food allergy, infection.
Symptoms: Loose badly formed stool.
Diagnosis: As per symptom.
Treatment: Removal of cause, medicine. If it persists for more than 24 hours see a vet.

Cat who died of urinary tract infection

Urinary Tract Infections (UTI).  Or FLUTD – Feline Urinary Tract Disease and FUS – Feline Urologic Disorder. These are wider issues. Cystitis refers to bladder conditions.
Cause: plugged, obstructed urethra (tube from bladder to exterior) by crystals, crystals/stones in urinary tract, alkaline urine, bacterial infection causing cystitis, inflammation of urethra, diet (dry food), water intake insufficient, stress generally, stress due to environmental issues (i.e. moving, separation anxiety).
Symptoms: Normally in cats older than 1. Lengthy squatting, straining, going to litter often, urination often, bloody urination, drops of bloody urination, urination in wrong place, licking penis, licking vulva, vocalising during urination.
Diagnosis: Plugged urethra (1): distended abdomen, straining at toilet & no urine. Loss of appetite, vomiting. Cystitis (2): passing blood (vet can check sample), cystoscopy, biopsy, ultrasound, X-ray.
Treatment: (1) See vet immediately. (2) Antibiotics (i.e. Doxycycline and Clavamox), eliminate cause of stress, canned food, water added to food (fish), cat behaviorist, Feliway, anti-anxiety drugs, Hills c/d,

cat uri

Upper Respiratory Infection (URI)
Note: Most common infectious disease in domestic cats.
Cause: 80-90% are caused by: rhinotracheitis virus – feline herpesvirus (Feline herpes virus type 1 – FHV-1) , feline calcivirus (FCV). Other causes: chlamydia.
Symptoms: Depending on virus: sneezing, runny nose & eyes, pink eye, fever, thick eye/nose discharge, corneal/mouth ulcers, dehydration, anorexia. Sinusitis, fatalities in kittens.
Diagnosis: Observation of symptoms & further testing for underlying problems: distemper or kennel cough, for example.
Treatment: Antibiotics for secondary bacterial infections, antiherpes eye drops. Tasty food. Prevention: vaccines.

cat vomiting

Note: Vomiting is a symptom not a disease.
Cause:  Swallowing indigestible item, intestinal parasites, overeating, eating too fast, infectious disease (distemper or panleuk, IBD, tonsillitis, sore throat, infected uterus), kidney or liver disease, central nervous system disorder, ingesting poison or drug. Peritonitis.
Symptoms: Throwing up stomach contents. Dehydration can follow & can accompany diarrhea.
Diagnosis: Observing how and when vomiting occurs and subsequent tests for underlying disease(s). Vomiting not connected to eating: see vet. Vomiting 1x or 2x is OK. Watch & treat at home.
Treatment: See vet if it lasts more than 24 hrs. One off vomiting is normal. If more in 24 hrs: rest stomach for 12 hrs and then water. Observe…vet?

diabetic cat

Feline Diabetes (diabetes mellitus – sugar diabetes)
Note: Affects 1 in 400 cats. High risk cats: neutered males over 10 yrs old and 15 lbs in weight.
Cause: (1) Inadequate production  of insulin in the pancreas (2) inadequate response of body’s cells to insulin. Leads to high blood sugar levels (hyperglycemia). Phantom causes: pancreatitis, hyperthyroidism, medications can mimic/cause diabetes. Obesity predisposes cats to diabetes. Burmese are predisposed. High carbohydrate diet (dry cat food?)
Symptoms: Initially increased appetite, then lower appetite. Increased urination, increased drinking. Weight loss. Vomiting, weakness, walking down on hocks.
Diagnosis: Lab test reveal high blood sugar levels and glucose in the urine.
Treatment: Depends on type of diabetes. Includes dietary management, daily injections of insulin. Glucose level testing. Oral medication.

cat with skin allergy


Skin Allergies – refers to allergic reactions manifested in skin conditions and itching.
Cause: Immune system overreacting to food: chicken corn, wheat; airborne allergen(s): pollens, house dust, molds; parasites, vaccinations, insect bite, autoimmune disease, drug reaction, acids, alkalies, detergents, soaps flea powder, shampoo, poison ivy, poison oak, certain plants, water dishes, bacterial and fungal infections, insecticide, litter box.
Symptoms: Itchy rash on head, neck, back, swollen eyelids, hair loss, oozing sores, inflamed ears, small bumps and crusts on skin, raw patches of skin, red itchy bumps on skin where hair is thin
Diagnosis: Feeding diet without suspected food, exposing cat to allergen, observing symptoms, intradermal skin test,
Treatment: Hypoallergenic diet, remove fleas/parasites, cortisone tablets, antihistamines, omega-3 fatty acids, antibiotic/steroid ointment, aloe ointments, hyposensitisation, isolate allergen and exclude it, oral corticosteroids, allergy shots, immune therapy, bathing.

cat with constipation

Constipation and colitis (inflammation of colon).
Note: Colitis causes painful defecation & straining – distinguish from constipation. Manx cat predisposed to constipation.
Cause: Infrequent bowel movement, dehydration (renal disease), not drinking enough, hairballs, ingesting indigestible objects, dirty litter box, unfamiliar environment (stress), older cat (weak muscles), megacolon, nerve damage due to broken pelvis.
Symptoms: Infrequent passage of small, hard stools, straining and pain during defecation, lethargy, bloated, pick at food, vomiting hairball, hair in feces. Distinguish straining in urination (UTI).
Diagnosis: observing symptoms.
Treatment: High fiber diet, hairball prevention cat food, low carbohydrate food, feed only wet cat food + 1 teaspoon of rice bran/powdered psyllium. Bulk laxatives: wheat bran, canned pumpkin, Metamucil, Lactulose, pediatric glycerin suppositories, stimulant laxatives (short term): Kat-a-lax, Laxatone (USA) – see vet first. Keep litter clean. Exercise.

cat with ear infection


Ear Infections
Note: Accurate diagnosis is important – see vet.
Cause: Parasites: head mite, fleas, ear mites. Bacterial secondary infections, fungus infection, yeast infection, foreign bodies causing infection, polyps (growth) caused by infections, inner ear infection,
Symptoms: Itching, ear discharge, excess ear wax, head shaking, scratching, pawing at ears, odor from ear, head titled, tender ears, inflamed ear, severe pain (middle ear) crouching low & head tilt, unsteady gait, vomiting, staggering, falling (inner ear)
Diagnosis: Ear mites: removing sample of ear wax and examining under magnifying glass. Culture test for type of bacteria. Middle ear: veterinary exam of ear drum  & X-ray. Inner ear: see symptoms – vestibular disease.
Treatment: Ear mites: clean ears, medicate: i.e. Nolvamite, Mitaclear (USA), insecticide dips, trim claws to minimise scratch. Bacterial infection: dissolve wax, clean ear, topical antibiotic ear medication. Oral antibiotics. Fungal: i.e. Nystatin, thiabendazole, Miconazole (USA). Foreign body: vet removes object. Polyps: surgery. Middle & inner ear: antibiotics possible surgery.

hyperthyroidism in a cat

Hyperthyroidism (thyroid cancer)
Cause: Increased thyroid production caused by benign or malignant cancer in usually older cats. Exposure to secondhand hand smoke.
Symptoms: Increase in appetite, wolf down food, search for food, highly active old cat, weight loss, vomiting, panting,
Diagnosis: Palpation under chin may feel small lump or lump on both sides, blood work (analysis) to check raised thyroid levels, check kidney function, check heart for damage due to raised metabolic rate. Check for raised blood pressure.
Treatment: Oral medication: Methimazole (USA). Other methods of administering this drug. Surgery. Radioactive iodine.

Cat illnesses — Photo credits and a bit about the cats in the pictures:

  • Hobbes – photo by versageek (the human companion) – at 2007 was 18 years of age. She vomited frequently and the vet could no discover the cause so she was given steroids, a kind of last resort treatment. She had lost her appetite too. Vomiting is not one of the cat illnesses if it is transient.
  • Stinky – photo by Mel B. Stinky was 17 years of age when she was diagnosed with diabetes, one of the cat  illnesses that is on the increase.
  • Johnny, Goldie and Pippa are or were cared for by Elisa Black-Taylor, one of America’s best cat caretakers and a cat rescuers. She know how to deal with cat illnesses.
  • Unknown cat – This is a cat flea allergy dermatitis picture, a photograph taken by the veterinarians or their associates at the Cuyahoga Falls Veterinary Clinic. This photo has been used with permission
    for teaching educational purposes at (PoC). I want to thank Ryan G. Gates, DVM of the clinic
    for granting permission. Picture has been modified here.
  • Unknown cat – constipation and hyperthyroidism. Picture taken at by Nottingham Vet School. The “constipation cat” presented with constipation and possible hyperthyroidism. The other cat had hyperthyroidism.
  • Henry – ear infection – photo by charlie applebottom.

Cat illnesses to home page.


7 thoughts on “Cat Illnesses – most common”

  1. My 8 year old calico cat who has always been an indoor kitty just started sneezing out of the blue. She was up all night, sneezing constantly. We have been staying in a hotel and at friends houses for the past 2 weeks while our home is being finished. Could she be sick or just have allergies from being in different places? I am worried sick!

    • Hi Maria, thanks for visiting and asking. It is not clear from your comment where your cat is. I presume she is with you at your friend’s house. The change in her environment appears to have caused it. That would imply allergy as you suggest. Has she been in contact with other cats recently? She may have caught a viral infection.

      It could be a foreign body stuck in the nose but that is a big guess. If there is something stuck in the nose a cat sneezes vigorously in a group of several sneezes. Then it will happen again sometimes later. Is there a nasal discharge? If it is clear liquid coming from both nostrils it will be a virus. If it is grey/yellow thick discharge it will be a bacterial infection. If it is from one nostril it might be a foreign body causing a bacterial infection.

      It might be an allergy to something in the air or on the floor – there are many possibilities. Getting back to your home will provide the answer. If there is no nasal discharge it is most likely something like dust in the air. Getting back to you home will verify whether it is caused by the environment in which she now lives.

      Good luck.

    • The question that I have for you is this: has this just happened or has there been some time that has passed during which there have been signs of an infection? If your cat can hardly open his eye today but yesterday and the day before that he was all right then this must be an injury. I would certainly look at it very carefully to check for signs of injury and if in doubt of course your cat should see a veterinarian. If on the other hand it’s an infection which has developed into a bacterial infection which has caused a disease such as conjunctivitis then once again you need is a vegetarian. These 2 causes come to my mind immediately but there may well be many others.

      Thanks for commenting and visiting.

  2. My cat is sneezing and sleeping alot she has black spots on her nose but she is a calico however she moves when i touch the spots

    • The black spots on your cat’s nose is due to pigmentation which is quite normal. The reason why she moves when you touch the spots is because she is a bit uncertain about you touching the tip of her nose but in my estimation there is nothing wrong with her nose. However, if your cat is sneezing a lot then she quite possibly has either a viral or bacterial infection what is called a upper respiratory tract infection or URI. You should see a veterinarian I’m afraid. Thank you for visiting.

  3. my cat is sneezing a lot and has a runny nose.he has had jab for cat flu he is nearly finished kesium for tummy upset/infection. off food a little bit. been like this for a few days. should I take him to vet or is there anything I can do.


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