This paper presents a novel concept of multi-drop path-based multidestination message passing on switch-based irregular networks. First, the multi-drop mechanism is defined with an associated header encoding scheme, and this mechanism is used to develop path-based multidestination worms. Next, a method is proposed to identify valid multidestination paths on arbitrary irregular networks with a typical deadlock-free routing. Then, the deadlock-free property of multi-drop path-based worms is emphasized. Using the above concepts, three mul- ticast algorithms are proposed: multi-drop path-based greedy (MDP -G), multi-drop path-based less-greedy (MDP-LG), and multi-drop path- based binomial (MDP-B). The proposed algorithms are compared with each other and with the best unicast based algorithm, the CCO [5], for a range of system and technological parameters. The MDP-LG scheme is shown to be the best to implement multicast with reduced latency.