Feline calicivirus (FCV) is another highly infectious pathogen of cats, with a widespread distribution in the cat population [5] and [6]. Studies have shown that the prevalence is broadly related to the number of cats in a specific household or other location; with, for example, privately owned animals present in small numbers [7] having a lower prevalence than those kept in a cat shelter. FCV has significant genetic diversity with the potential to produce multiple strains, and as a result the range of clinical signs following infection can be broad, with the most common being oral ulceration, with ocular and nasal discharge and pneumonia also observed [8]. The presence of antibodies, either as maternally-derived or induced through active vaccination, has been demonstrated to play a role in reducing or eliminating the clinical signs of a FCV challenge [9], but does not prevent infection