Gastro-intestinal nematodes can cause clinical disease in animals and loss of production:
- Ostertagia ostertagi has potentially the most impact economically and can cause diarrhoea, thirst, bottle jaw and weight loss.
- Cooperia oncophora affects calves in their first grazing season. It is associated with loss of appetite and poor weight gain.1
Rainfall, temperature, previous exposure and concurrent disease are all additional risk factors of GI disease.