Cochliomyiahominivorax (Coquerel, 1858)
Cochliomyiahominivorax, the New World screwworm, is indiscriminant in its choice of hosts, and cats will be infested by this fly. The female lays batches of eggs in rows on the edge of any small would in the skin, and after about one-half to one-day, the eggs hatch and the larvae crawl into the would site. The larvae feed on the wounds for about a week and then fall to the ground where they burrow into the soil prior to pupation. The lesions produced can be severe and can attract other species of flies that will secondarily establish in the wound. Such lesions can be very debilitating and can become life threatening. The screwworm maggots can be identified by their very black tracheae that are present in the posterior of the body and which are easy to observe upon dissection. Fortunately, due to a successful control program that involves the release of irradiation sterilized males, Cochliomyia hominivorax only occurs in the America south of Mexico.
Cats have been infested with this parasite. Vignau and Arias (1997) observed cases in 9 cats in Argentina during January through May. Santa Cruz and Lombardero (1987) found it in 1 of 50 cats examined in Correintes City, Argentina.
Santa Cruz A.M.,. Lombardero O.J. 1987. Resultados parasitologicos de 50 necropsias de gatos de la ciudad de Corrientes. Vet Argentina 4:735-739.
Vignau M.L., Arias D.O. 1997. Myiasis cutaneo ulcerosas en pequenos animales. Parasitologia al Dia. 21:36 39.