Oesophagostomum spp. are relatively large worms and can be found in fairly small numbers in goats throughout the United States. These worms feed on blood and can contribute to the overall anemia primarily attributed to barber pole worm (H. contortus). Although this worm resides in the large intestine, the larvae are found in the mucosa of both the small and large intestine where they form nodules, thus the name "nodular worm." Once the larvae leave these nodules, they reside in the large intestine.
Trichuris spp. are usually found in small numbers throughout the United States. The posterior end of the worm is rather large and visible. The anterior end of the worm is thread-like, thus the name "whipworm." These worms are also blood feeders and, like Oesophagostomum, can contribute to anemia although neither one has as big a role in overall blood loss as barber pole worm. Female worms produce characteristic football shaped eggs with protruding plugs at each end.