5 Most Dangerous Cat Diseases

By Sarah Winkler, Animal Planet

According to the Humane Society of the United States, there are more than 70 million feral and stray cats roaming the streets. Because stray cats often carry dangerous diseases, the best thing that you can do to protect your domesticated cat against serious illness is to keep it indoors. By staying inside, your cat is less likely to fight with other animals and risk the chance of spreading diseases through wounds. You’ll also keep it away from infection-spreading parasites, including fleas and ticks, and prevent the kidney failure that can come as a result of ingesting poisonous substances such as antifreeze.

Outdoor cats and those that live in multi-cat homes have the highest risk of disease. However, indoor cats and “only cats” can get sick, too. The good news about cat illnesses is that most are easily preventable; the bad news is that once your cat contracts an illness, it can be very difficult to treat. It’s also important to keep in mind that even minor ailments can suggest major health problems. But some cat diseases are more dangerous than others. Read on to learn about some of the most serious ones.

5: Feline Leukemia Virus

Feline leukemia is a disease that spreads through urine, nose discharge and saliva. Cats can catch the disease through bites, sharing food and water bowls, and from simply living together. Mother cats can pass the disease along to their kittens, and kittens are more likely to contract the disease than adult cats.

Some cats will immediately become ill upon contracting the virus; however, in other cats, symptoms of the disease will not manifest for several weeks. Feline leukemia can result in a number of conditions, including system-wide infections, diarrhea, skin infections, eye disease, respiratory tract infections, bladder infections, infertility, anemia and cancer. Any severe chronic illness can be a sign of feline leukemia.

Although there is no cure for feline leukemia, the disease is easily preventable. Keeping cats indoors, restricting exposure to other cats, maintaining a clean living environment and ensuring your cat is vaccinated can all help prevent feline leukemia. According to the Merck Veterinary Manual, veterinarians rarely see cases of feline leukemia among vaccinated cat populations.

4: Feline Immunodeficiency Virus

Unlike human immunodeficiency virus (HIV), sexual contact is not a major factor in transmitting feline immunodeficiency virus (FIV). It primarily spreads through bite wounds, and outdoor cats and territorial tomcats are most susceptible to infection. However, unlike feline leukemia, casual contact through sharing food and water bowls doesn’t significantly increase risk of contracting FIV. Although a mother cat may pass the virus along to her kittens, this happens rarely.

Once the virus enters the bloodstream, it can remain dormant until it progresses into an active disease. FIV is terminal, and because it targets the immune system, cats that have the disease run an increased risk of enlarged lymph nodes, ulcers of the tongue, inflamed gums, progressive weight loss, poor coat and skin disease, diarrhea, anemia, eye disease and cancer.

To prevent FIV, keep your cat indoors and up to date on vaccinations. According to CatHealth.com, vaccinating for this virus after your cat is at least 8 weeks old can prevent infection about 60 to 80 percent of the time after three doses.

3: Kidney Disease/Renal Failure

Renal failure, which is caused by kidney disease, is one of the leading causes of death in older cats. Causes for kidney disease include age, genetics and environmental factors such as access ingesting poisonous substances. Renal failure in cats can take two forms: acute or chronic. Acute renal failure is associated with a sudden stop of kidney function, while chronic renal failure results from a progressive deterioration of kidney function.

A number of symptoms can show up as a result of kidney disease, including excessive urination, increased thirst, nausea, a grinding or cracking sound in the jaw, vomiting, dehydration, constipation, loss of appetite, weight loss, halitosis (ammonia smell) and lethargy. If your cat is experiencing any of these symptoms, your vet can test for kidney disease and renal failure. Urinalysis can test to see if the cat’s urine is diluted, which indicates that its kidneys aren’t passing waste. Blood tests can check on creatinine and BUN (blood urea nitrogen) levels. An elevated creatinine level can be a sign of loss of kidney function.

Although there is no cure for feline kidney disease, you can treat it through adjustments to your cat’s diet, medication and diuresis (hydration therapy). According to the Merck Veterinary Manual, the animal receiving treatment can survive for long periods of time using only 5 to 8 percent of their renal tissue.

2: Feline Panleukopenia (Feline Distemper)

Feline panleukopenia, also known as feline distemper, is a highly contagious viral disease in cats. Kittens are most at risk, and they almost always die — even if given treatment — after contracting the disease. It can spread through bodily fluids, feces and fleas, and is usually transmitted by contaminated food and water bowls, litter trays and clothing.

Feline distemper affects cats’ intestinal tract and attacks their immune systems. Cats suffering from the disease are likely to experience diarrhea, vomiting, dehydration, malnutrition and anemia. Symptoms include depression, loss of appetite, lethargy, and tail and back leg biting. A vet can diagnose feline panleukopenia through fecal and blood tests.

Treatment of feline panleukopenia is aggressive, since the disease can kill within a day of contraction. Cats usually receive blood transfusions, antibiotics and vitamin injections to combat the disease. According to The Merck Veterinary Manual, vets see few cases of feline panleukopenia among vaccinated cats, but infection rates remain high in unvaccinated populations. In order to prevent feline panleukemia, you should vaccinate your cat and keep it away from unvaccinated and feral animals.

1: Feline Rabies

According to The Merck Veterinary Manual, cats are reported rabid more often than any other domesticated animal in the United States. And feline rabies is one of the most dangerous cat diseases, because it doesn’t infect just cats — it can be passed along to humans, too. Rather than cat-to-cat transmission, feline rabies usually spreads to cats through bites from wild animals. This debilitating and degenerative disease attacks the nervous system.

Feline rabies can be deceptively slow moving; the disease can incubate in a cat’s system for as many as two to five weeks, according to VetInfo.com. Symptoms include poor coordination, conjunctivitis, yowling, drooling, fever, strange behavior, depression and weight loss. There is no treatment or cure for feline rabies. The best you can do is make sure your cat is vaccinated against the disease, and keep it inside to avoid contact with infected animals.

[Learn more about cat health]

Top 10 Cat Health Questions
5 Pet Health Myths
Top 10 Common Pet Toxins
10 Cancer Warning Signs in Pets


Ann Razumovskaya
Ann Razumovskaya4 years ago

Feline calicivirus and feline viral rhinotracheitis (FVR) are very contagious and highly dangerous too. Vaccinate your animals, it's way more easier for your pets than treatment and way more cheaper. 2 of my cats have contracted panleukopenia 3 weeks ago, thank gods now they are safe and healthy. It was my fault - i haven't vaccinated them this year. Beware and don't repeat my mistakes!

Genoveva M.
Genoveva M M4 years ago

Great article, thanks for the information.

Judy S.
Judy S4 years ago

There is also Cancer which is very common in cats that were fixed later in the years. My cat actually has had 2 Mammry tumors removed. Its very sad to see them go through that. So far since the second one has been removed she is better and no signs of any more tumors. PRAISE GOD!

Danuta Watola
Danuta W4 years ago

Thank you for the information.

Nelson Baker
Nelson Baker5 years ago

Animals are very intelligent.

sima j.
sima jalil5 years ago

Thanks Christin, will look for cat traps (didnt know you actually HAD stuff like that !)

Christin Shives
Christin Shives5 years ago

Sima J. There are sprays out there that you can spray on your fence line, etc. The best way however is to rent a couple of traps and trap the cats in a humane way, turn them over to your Humane Society or other organization to get them spayed and re released. But no more babies.

sima j.
sima jalil5 years ago

Does anyone know how I can get rid of stray cats in a humane way? There are about 6-8 strays that keep coming into my back yard, shitting all over the the place and generally making a nuisance of themselves. For some strange reason they don't dig a hole when they shit, just do it on the hard ground. I seem to be cleaning it up all the time.
There is no municipal system of getting rid of strays where i live. The people next door keep giving them food as they feel "sorry" for them, and in spite of complaints have done nothing. And every 3 months there is a new litter that adds to the problem.

Desperate! Need help as I dont want to resort to horrible things like poison.

Laura G.
Laura Garrett5 years ago

Feline infectious peritonitis should definitely be on this list; it is highly dangerous because it is both contagious AND there is no vaccine to prevent it nor cure it once your cat has it. I lost my beloved Indy to it last year, and it broke my heart.

Rosemary Rannes

Very much appreciated Samantha. Our Kismet aka Kizzy is now 14. We fear we are 'losing' him:(
Time to go to the Vet ...