The highest concentration is found in the saliva, but may also be found in the tears, urine and feces of infected cats. The virus does not survive well in the environment and is killed with disinfectants, soap, heating, and drying. Only under optimal conditions for the virus will it survive for a period of 24-48 hours. Cats may become infected via the oronasal route if they come in contact with an infected cat. There is a high incidence of infection in multiple cat households.
Young kittens are more susceptible than adult cats.
A large quantity of virus or prolonged exposure to the virus is needed to infect adult cats. The virus is transmitted to kittens through the placenta or the milk of an infected queen. Male, 4-5 years of age, and free roaming habitat, are in a higher risk group. Exposure to the virus does not always produce infection. Infection will result from the virus entering through ocular, oral and nasal mucous membranes.