In natural domestic cat populations, FIV is mainly transmitted through bites arising from aggressive or sexual contacts [3, [6] [7] [8] [9] [10] . As a consequence, the spread of FIV in domestic cat populations is highly influenced by the mating system; a higher FIV prevalence is observed in aggressive and polygynous cat populations that involve more fights and bites than in much less aggressive and promiscuous urban ones [8, 9] , where FIV can be absent [11] .