Written about by ancient Greeks, Romans, and Egyptians. Closely related to a species in pigs Ascaris suum . May have originally been the same species. None if only a few adults in intestine.
Large numbers compete for food and cause intestinal discomfort.
Migrating juveniles may cause inflammation in various organs. Adults may wander upstream or down to various organs, or rupture the intestinal tract. Diagnosis by finding eggs in fecal smears. Similar to human ascarids but with many alternative pathways. May utilize paratenic hosts.