Ostertagiosis (O. ostertagi)

GastrointestinalBovineNew

Key Points

Ostertagiosis is a parasitic gastrointestinal disease, caused by Ostertagia ostertagi, that leads to abomasal gastric gland damage, impaired hydrochloric acid secretion and disruption of digestion
Most commonly seen in young cattle
There are 2 forms of disease:
- Type I – cumulative L3 larvae ingestion in first-season grazing cattle, typically occurs in late summer / autumn
- Type II – mass emergence of hypobiosed L4 larvae in older cattle, typically occurs in late winter / spring
Clinical signs include weight loss or poor weight gain, diarrhoea and submandibular oedema
Diagnosis is typically based on clinical presentation and grazing history
- FECs and serum pepsinogen levels can be used to support a diagnosis
Anthelmintics are the mainstay of treatment
Prevention strategies centre on responsible anthelmintic use and good grazing management

Differential Diagnoses

Cooperiosis (Cooperia spp.)
Coccidiosis
Fascioliasis (F. hepatica)

Educational content only. This factsheet is for general veterinary education and is not a substitute for professional veterinary advice, diagnosis, or treatment. Not for use in an emergency — contact a veterinarian or emergency service. Full disclaimer →