Trichostrongylus axei is the scientific name for the small stomach worm/abomasal worm. The small stomach worm (hairworm) of horses, Trichostrongylus axei, is also found in ruminants and, consequently, is generally a clinical problem only in horses commingled or rotated on pasture with ruminants. Adult T axei are slender and measure up to 8 mm long.
Details of the life cycle in Equidae have not been carefully studied, but it is known that the larvae penetrate the mucosa. These worms produce a chronic catarrhal gastritis, which may result in weight loss. The lesions comprise nodular areas of thickened mucosa surrounded by a zone of congestion and covered with a variable amount of mucus.