CASP3 and infection: To assay if an ISAV infection with a MOI of 1 would induce effector caspase activity, and whether there were cell type or strain specific differences, Caspase 3/7 activity was measured in SHK-1, TO and ASK cells infected with ISAV 2, 4, 7 or 10 during the course of infection (days 1, 3, 5, 7 and 9).