The goat or sheep is infected when they graze on grass where the larvae have migrated. The larvae travel to the wall of the abomasum or the small intestine where they go through a molt. They then leave the wall to live freely in the lumen of the intestine or stomach. There they develop into adults and are laying eggs within 21 days after infection. These parasitic worms primarily cause problems in young animals.
Adults can carry heavy infections but show little evidence.
The intestinal species cause more problems than T. axei which lives in the abomasum. The presence of the intestinal species cause diarrhea, weight loss and loss of appetite. The worms suck blood from the lining of the intestines which causes irritation and swelling of the intestinal membrane. The damaged mucosa results in malabsorption, impaired digestion and protein loss. Heavy infestations may prove to be fatal to the young animal.