a helminthiasis of sheep, goats, and other ruminants, caused by the large-mouth bowel worm (Chabertia ovina), a nematode that parasitizes the large intestine. The disease occurs throughout the world. The worms range in length from 13 to 26 mm and develop without the participation of intermediate hosts. Larvae are hatched from eggs in the outside environment. Animals become infested in pasture after swallowing larvae in feed, grass, and water from puddles. In the host, the larvae penetrate into the intestinal walls, where they molt twice, emerge into the intestinal lumen, and grow into adult parasites. While migrating the larvae cause blood effusion and hemorrhaging of the intestinal wall. The adult parasites feed on blood, traumatizing the intestinal mucosa and leading to anemia.
In cases of severe infestation, animals suffer from exhaustion, diarrhea, loss of fur, and lack of appetite. Chabertia infestation is frequently fatal. Treatment consists in dehelminthization with phenothiazine. The most effective preventive measure is dehelminthization of the animals before they are taken out to pasture.