Ancylostoma caninum is a species of nematode known as a hookworm, which principally infects the small intestine of dogs. The result of A. caninum infection ranges from asymptomatic cases to death of the dog; better nourishment, increasing age, prior A. caninum exposure or vaccination are all linked to improved survival. Other hosts include carnivores such as wolves, foxes and cats with a small number of cases having been reported in humans.