Helminthiasis due to hookworm infestations in humans and Haemonchus contortus in sheep cause untold levels of disease and economic losses worldwide. Drug resistance is an ever-growing problem with pathogenic helminths. Thus, there is a critical need for new treatment strategies for hookworms and H. contortus that depends on animal models. Because hook- worms and H. contortus are obligate parasites, they can only be maintained using live animals. This review describes use of the Syrian golden hamster to propagate hookworms and Mongolian gerbil to propagate H. contortus.