*Where there is no effective treatment once infected E.g. [[Immunodeficiencies - WikiBlood#Feline Leukaemia Virus (FeLV)|FeLV]], FIV
+
*Where disease is life-threatening E.g. Canine Parvovirus
+
*To prevent the spread of disease by virus excretion E.g. Rabies, FMDV
−
*Where there is no effective treatment once infected
+
The goal is to vaccinate 90% of the population to reduce the amount of '''endemic''' virus until no new infections occur. Once the disease risk is low, vaccination can be replaced by an eradication or quarantine programme