Cat flu is an airborne virus. The main method of spread is by direct contact between cats. Large amounts of the virus is present in saliva, tears and nasal secretions, and it is commonly spread by cats sniffing each other, grooming each other and sharing feeding bowls. One droplet of the secreted viruses can travel up to two metres. Some strains of virus can be spread via urine and faeces.
There are two forms of cat flu: feline calici virus (FCV) and feline herpes virus (FHV). Feline herpes virus causes the most serious cases. The incubation period for feline calici virus is approximately 7 days. Feline herpes virus has an incubation period of approximately one day.
Cats can not catch “human” flu from humans nor can humans or other animals catch cat flu.
The main signs of cat flu are sneezing and runny eyes. The cat’s temperature will increase and it’s glands may enlarge. It could temporarily lose it’s sense of smell due to a blocked nose. It will often lose its appetite. Calci virus can cause chronic gingivitis and in extreme cases mouth ulcers. This can make eating extremely painful and may cause the cat to salivate. The cat may not necessarily show signs of respiratory problems. Feline herpes virus can cause severe ulceration of the cornea (eyes). Cat flu can progress to severe pneumonia if left untreated.
After cats have been infected they can continue to spread the virus to other cats. Note that cats with feline herpes virus will carry the virus for life – even in spite of vaccination - and the condition may flare up in stressful situations. Cats suffering from feline calici virus may recover and not be affected in future, but do be cautious when introducing them to other cats.
Make sure any cat introduced into the household is fully vaccinated.
It is important to have [annual vaccinations] done to protect the cat from these viruses. Please note however that there are many different strains of cat flu and vaccination will not necessarily protect against all of them.