Whether you are considering bringing another cat into your home, booking your cat into a kennel, or even just concerned about your cat mixing with other neighborhood cats, there are many different infectious cat diseases to be aware of.

Key Takeaways:
  • Cats can transmit diseases through sneezing, coughing, grooming, and sharing food/water bowls.
  • Commonly transmitted feline diseases include leukemia, immunodeficiency virus, and respiratory infections.
  • To reduce cat diseases, routine vaccinations are essential. Additionally, maintaining a clean environment, feeding a balanced diet, and regular vet check-ups can help prevent disease transmission.

These diseases can spread from cat to cat and sometimes even from cat to human and vice versa. In this article, we will discuss some of the more common communicable cat diseases and how they are transmitted.

How Do Cats Transmit Diseases to Other Cats?

Cats can transmit diseases through sneezing, coughing, grooming, and sharing food/water bowls. Commonly transmitted feline diseases include leukemia, immunodeficiency virus, and respiratory infections. Clean living spaces, good hygiene practices, and vaccines can help prevent disease spread. 

Common Infectious Cat Diseases

Many communicable cat diseases can be spread by more than one route of infection. Let’s take a look at some of the more common infectious cat diseases and how they are transmitted. 

Upper Respiratory Infections

Upper respiratory infections in cats (often referred to as cat flu) are very common and are predominantly caused by viruses such as Feline Calicivirus (FCV) and Feline Herpes Virus (FHV). They can also be caused by bacteria such as Chlamydophila, Mycoplasmas, and Bordetella bronchiseptica.

Affected cats are often infected with more than one of these viruses and bacteria at the same time. They are predominately spread via nasal secretions and saliva of cats that are in close contact with each other.

Feline Leukemia Virus (FeLV)

Feline Leukemia Virus (FeLV) is one of the most common communicable cat diseases and can be fatal. It can lead to cancer, blood disorders, and immunodeficiency. It is most frequently transmitted via contact with another cat’s infected saliva but the virus is also shed in nasal secretions, blood, urine, feces, in utero, and via milk.

In practical terms, this means that FeLV can be spread from a bite wound from an infected cat, mutual grooming, or the sharing of litter boxes or food and water bowls. It can also be spread to kittens in the womb from an infected mother cat, or via her milk once the kittens are born and nursing. 

Feline Immunodeficiency Virus (FIV)

Feline Immunodeficiency Virus (FIV) is one of the more common infectious cat diseases and attacks the immune system of infected cats, making them much more susceptible to other diseases. Although it can ultimately be fatal, many cats can live for years before they develop any symptoms of the virus.

It is usually spread via a bite wound from an infected cat. Therefore, the cats most at risk of acquiring FIV are un-neutered male cats that are prone to fighting. FIV can also be transmitted to an infected mother cat’s kittens although this is less common.

Feline Panleukopenia (FP)

Feline Panleukopenia (FP) is a highly contagious disease caused by the cat parvovirus. It causes severe gastrointestinal signs such as vomiting and diarrhea, along with blood disorders and neurological signs. It most commonly affects kittens and can be fatal.

The virus is shed in the bodily fluids of infected cats including saliva, urine, and feces. It can also be spread via fleas that have bitten an infected cat. Although an infected cat is only contagious for a couple of days, the virus can live for up to a year in the environment on things such as food bowls, bedding, and surfaces.

Feline Infectious Peritonitis (FIP)

Feline Infectious Peritonitis (FIP) is caused by the cat coronavirus (which is different from the coronavirus that causes COVID-19 in people). Infection with coronavirus is very common in cats and infected cats shed the virus in their feces.

It is transmitted when another cat ingests the virus but often does not cause any symptoms to develop, or causes mild diarrhea. Rarely though, the coronavirus mutates to cause FIP in certain cats. Although this is very uncommon, there is no cure for FIP and it is almost always fatal. 

Cat Diseases Transmissible to Humans

Zoonoses, diseases that can be passed between animals and humans, aren't common but do exist. From cats, humans can contract Ringworm through direct contact, Bartonella or 'cat scratch fever' via fleas and ticks, and Toxoplasmosis from cat feces. If you're worried about potential zoonotic diseases, it's best to consult your doctor.

Here's a breakdown of each possible cat disease that can be passed to humans: 


Ringworm (dermatophytosis) is a fungal infection that is spread through direct contact from one cat to another or a cat to a human. It is also possible for a human to spread ringworm to a cat. In cats, it usually results in bald patches that are flaky and dry. Sometimes cats can be asymptomatic but it is still possible for them to pass the infection to any humans that they may come into contact with.

Bartonella (Cat Scratch Fever)

Feline Bartonella (nicknamed ‘cat scratch fever’) is a bacterial disease spread by fleas and ticks. The bacteria are found in the feces of these parasites and cats are infected when they ingest the feces through licking or grooming. The disease can be transmitted to humans if they are bitten or scratched by an infected cat.


Toxoplasmosis is an infection caused by a parasite called Toxoplasma gondii. Cats are usually infected by eating infected rodents. They can then shed the parasite in their feces. Humans can be infected by accidental ingestion of the parasitic cyst that is passed in cat feces.

Toxoplasma rarely causes disease in cats or humans but pregnant women should take particular care when handling cat feces or cleaning the litter box. This is because in very rare cases, infection during pregnancy can result in birth defects or abortion.

Ways to Reduce the Likelihood of Disease Transmission

There are many ways in which the transmission of communicable cat diseases can be reduced. Effective cat vaccinations are widely available for FeLV, FP, and cat flu infectious agents. These can greatly reduce the risk of transmission between cats, as well as the development of associated disease symptoms.

Ensuring that male cats are neutered reduces the likelihood of fighting and therefore the spread of cat diseases via infected bites or scratches. Always practice good hygiene which will greatly reduce the risk of transmission of cat infectious diseases via food bowls, litter trays, and bedding. 

If you have a cat that you suspect may be carrying an infectious disease, then isolate him from any other cats where possible and contact your veterinarian for further advice.