By J. Russell Stothard, Liverpool School of Tropical Medicine
On the left are Schistosoma bovis collected from the gut mesenteries of an African cow, and on the right are paramphistomes (stomach flukes of ruminants that mainly affect cattle and sheep) collected from the stomach of the same cow. S. bovis typically causes low mortality but continuous poor health and poor productivity of a herd. Only the immature paramphistomes (flukes) cause disease and mortality, whereas the adult flukes do not cause obvious disease.
Image: Digital photograph of parasites.