Viruses and fungus in cats – what is important?

Viral infections and fungal infections (dermatomycosis skin fungus) are a common problem in households with several cats and in animal homes.

Viral infections

The so-called cat flu is particularly common (feline calicivirus = FCV; feline herpes virus = FHV) and can even occur in vaccinated cats in a lesser, but sometimes chronic form. Cat flu is normally not life-threatening. This is not the case with FIV (cat AIDS), FELV (feline leukaemia virus), FIP (feline infectious peritonitis) or parvovirus (cat plague). These viruses are incurable even with intensive treatment, and sadly are often deadly.


Routine injections protect against cat plague (parvovirus) and there is also a vaccination against FELV. FIP is not an infection in the strict sense of the word, but rather a mutation of a normal intestinal virus (coronavirus). It is not yet known how and why this mutation occurs in some cats.


The symptoms produced by a virus will depend on the cat’s immune system. The immune system can keep specific viruses under control for long periods of time, so that no symptoms occur even though the cat is infected. This is then referred to as a latent or persistent infection. There are reliable tests for FIV and FELV. So-called FIP tests, however, are still unreliable.

Skin fungus – dermatomycosis

Fungal infections are multifactor illnesses: fungal spores are everywhere and an illness only occurs when the cat’s immune system is weakened. This is why very young cats, cats with FIV or stressed cats (animal homes) are especially often affected by fungal diseases. The course of treatment will therefore always include strengthening the immune system of the sufferer.

What you can do to protect your cat

Preventive injections should be given according to risk of infection. Correct and long-lasting basic immunisation is especially important for your cat. Ask your vet what would be sensible and necessary for your cat and always seek advice. In cases of fungal infections, the exact type of infection must firstly be ascertained and then treated over a long period. Please remember that you could also get the skin fungus. 


You can strengthen your cat’s immune system by giving it a good, basic, cat-friendly diet along with a balanced mix of micronutrients, which can be served with treats, attractive snacks and/or paste. Beta-glucans have an especially positive effect on your cat’s immune system, along with specific antioxidants and vitamins.