The following parasites were recovered during necropsy from the cecum of a 4-year old cow with no deworming history. The cow was malnourished and with a high burden of gastrointestinal parasites.
Image 1: Worms recovered during necropsy.
Image 2: Anterior end cuticle inflations or vesicles.
Oesophagostomum radiatum, is a nematode that lives in the large intestine, primarily the cecum of cattle. The adults measure about 2 cm in length and their anterior end has cuticle inflations or vesicles (Image2). The eggs are 70 to 90 × 34 to 45 µm, thin shelled, and segmented when passed. Before current anthelmintics, Oesophagostomum was an important parasite during cool, wet seasons.
Oesophagostomins have a direct life cycle. Once in the gut, larvae penetrate the intestinal wall into the mucosa and molt to L4, which emerge in 7 to 10 days in a susceptible host. In hypersensitive hosts, nodules surrounding larvae are formed. The larvae may remain within the nodules for up to a year. These parasites are also called nodular worms.
Have feedback on the cases or a special case you would like to share? Please email us. We will appropriately credit all submittors for any cases and photos provided.