Experimental infection of the cockroach Periplaneta americana with Toxocara canis and the establishment of patent infections in pups

The possible role of the cockroach Periplaneta americana in the transmission of Toxocara canis eggs and larvae via faeces and tissue migration was studied. Cockroaches fed with 3 x 105 and 5 x 105 embryonated eggs were found to harbour viable eggs and larvae from days 1 to 5 post-infection (DPI). At necropsy on 5 DPI, eggs and larvae were also recovered from the rectal contents but not from the tissues of cockroaches. In addition patent infections were established in pups fed on infected faeces of cockroaches, with eggs first appearing in the faeces of pups at 38 DPI. Adult worms of T. canis were also recovered at necropsy. Therefore the importance of cockroaches as good mechanical disseminators of ascarid eggs, especially T. canis, is discussed.