Intestinal parasites are very common in wild felids and canids throughout Wyoming. Intestinal parasites generally don’t cause serious disease in their hosts, but in some cases they can be significant pathogens, causing tissue damage, nutritional stress, and emaciation. Significant numbers of internal parasites can weaken the host and allow establishment of other life threatening diseases.
Wild felids and canids are important reservoirs for cestodes and play a significant role in their transmission to other animals. These parasites require at least two different host species for completion of their lifecycles. Carnivores serve as the definitive host (where the parasite reaches sexual maturity and reproduction). Prey such as rabbits, deer, fish, and rodents serve as intermediate hosts. It is the intermediate host that is responsible for transmission from one definitive host to another. For cestodes, an intermediate host is required for development from the sexually immature stage to an infective larva. Adult worms occupy the small intestine, where they cause little or no problem for the host. The larval stages, on the other hand, occupy the skeletal muscle or other soft tissue of herbivores where they can be very pathogenic.