Observations on the Experimental Transfer of the Microfilariae of Dirofilaria immitis to the Mouse, Rat, and the Chick Embryo

Abstract

Blood containing microfilariae of D. immitis was inoculated intra-peritoneally into rats and mice. Washed larvae were also inoculated into the allantoic sac of the developing chick embryo. Viable larvae were observed in the peripheral circulation of the laboratory rodents as late as 3 weeks following injection. Pretreatment of rats with hyaluronidase, cortisone, and ACTH did not increase the number of circulating microfilariae found in the peripheral circulation of the rat. Of the number of larvae inoculated into the allantoic sac of the chick embryo, 50-60% appeared viable for a period of 6 days in this medium.