Cattlemen should be aware of the more important worms which occur, their debilitating effects, and their potential to flare up on occasion and cause serious problems and economic loss. Three species of roundworms are common parasites of cattle in Alberta. All live in the abomasum of cattle and suck blood while attached to the stomach wall. One, or all three species, may be present in an animal, and a few to several thousand may be present. Life Cycle of Abomasal Worms Adult worms are found close to the wall or attached to the abomasum.
Females lay microscopic eggs which pass to the ground in the manure.
Within a few days, a free-living larva develops within the egg which eventually hatches. This development may take only a few days in warmer months or several weeks during cooler weather. Cattle become infected with worms by eating food or drinking water contaminated with manure containing infective larvae. Within two to four weeks after eating the larva, the parasite develops into either a mature male or female worm. The life cycles of all the abomasal roundworms of cattle are similar.