The main infectious diseases in cats

Like us, cats are subject to infectious diseases caused by various pathogens such as viruses, bacteria, fungi and parasites. It's important to know what the main ones are, so you can take the appropriate measures to protect your cat's health, and that of other cats, by avoiding contagion.

Without being exhaustive, here's an overview of the major infectious diseases:

• Typhus or feline panleukopenia

This very serious disease is still common even in France. It is caused by a virus, specifically feline parvovirus, which infects all felids as well as raccoons, mink and foxes.

It manifests itself through diarrhea, vomiting, reduced immunity, anemia (reduced number of red blood cells) and extreme depression, even abortion in females.

In the absence of vaccination, it can infect cats of all ages, with a mortality rate of 90%, particularly in kittens.

This highly contagious disease can be transmitted either by direct fecal-oral contact, notably via highly infected feces; or, more frequently, by indirect contact, particularly via shoes or clothing contaminated by the virus. The virus is highly resistant in the external environment, where it can survive for several months. It is therefore difficult to combat. That's why this disease remains a real scourge, particularly in communities.

• Coryza

This is a respiratory syndrome, i.e. a set of symptoms affecting your cat's nose, eyes, mouth and respiratory tract. Clinical signs vary from mild forms with nasal discharge, conjunctivitis, mouth ulcers, sneezing, coughing, fever, loss of appetite... to severe forms with pneumonia and death. 

It can be caused by various viruses or bacteria, or even a combination of several of them. Among the main agents responsible are :

- viruses such as herpesvirus and calicivirus

- Bacteria, such as Bordetella Bronchiseptica or Chlamydia Felis.

In the latter case, Chlamydia is responsible for a more characteristic clinical picture, with marked ocular signs such as edema of the conjunctiva and ocular mucosa. The latter is sometimes so severe as to hide the eye.

Coryza particularly affects kittens and young cats living in groups.

Transmission is mainly by direct, close oro-nasal contact via infected nasal, ocular or oral secretions. For this reason, it is particularly prevalent in feline communities such as catteries, boarding kennels, shelters and multi-cat households. What's more, it's difficult to get rid of because, depending on the infectious agent responsible, some healthy, asymptomatic cats carry the disease. They may therefore become contaminated or fall ill again as a result of stress (change of environment, transport, moving house, high population density, etc.).

Did you know?

Even if your cat lives exclusively indoors, he's not immune to developing certain infectious diseases, either because we can be vectors with our clothes and shoes, or because he's a potential carrier from an early age, and can declare the disease later in life.

• Feline leukemia

Feline leukemia (FeLV) is a serious viral disease that is fatal once it has been declared. The incidence of this disease is now low in France, thanks to the combined use of screening tests and vaccination.

The most frequent signs are

- Anemia

- Immunodepression (lowered immune defenses), predisposing to other infections

- The appearance of lymphoma, a form of cancer that can affect various organs.     

The virus does not survive long in the environment. Transmission therefore occurs mainly through direct social contact, mainly via saliva, feces, nasal secretions or milk, but also through bites. Young kittens are particularly susceptible to this infection.

A particularly high-risk profile is that of the young, sociable cat who shares a litter tray with several other cats and grooms one another.

• Feline Immunodeficiency Virus (FIV)

Feline Immunodeficiency Virus (FIV) is a virus similar to AIDS in humans. It is therefore also a serious disease.

Similarly, it causes immunodeficiency, which is conducive to the development of various opportunistic infections. Clinical signs can therefore be varied, with gingivitis, rhinitis or chronic respiratory infection, urinary or kidney infections, recurrent abscesses in wounds...

FIV is mainly transmitted by biting during fights or mating. The risk of transmission is low in households with socially well-adapted cats.

In this case, the at-risk profile is more likely to be male, unneutered cats and/or stray cats, who are often fighters. However, transmission from infected mother to kittens is also possible.

Did you know?

A cat infected with feline leukemia or feline immunodeficiency virus can remain healthy for several years before developing the disease. This is why screening is so important to protect other cats from contamination.

Diagnosis and management of these different infectious diseases require various complementary tests, notably antigenic and/or PCR tests.

With the exception of bacterial infections, which may benefit from the use of a suitable antibiotic, there is often no specific treatment. Management is essentially symptomatic and supportive, with hospitalization in severe cases.

Ultimately, effective control of these diseases requires the combined use of diagnostic and screening tests, as well as preventive vaccination where available.

So, if you notice any of the symptoms mentioned above, or if your cat has never been tested for certain diseases, don't hesitate to ask your veterinarian for advices.

Dr BEGU C., Veterinary Doctor.