The nematodes of this genus, belonging to the order Trichurida, are easy to identify because in their adult form they have a whip-like body and are found in the cecum and colon of the host. The eggs of Trichuris spp. are lemon-shaped, yellowish-brown in colour, have two protruding opercula, and measure 70 to 80 µm long by 25 to 40 µm wide.

Infection in young ruminants is relatively common, with mild infections being mostly asymptomatic. Animals with high parasite loads may have dark stools, anaemia, and anorexia.

The lesions caused by the parasite can act as a gateway for other agents, favouring the appearance of secondary infections.


The blue bar represents the percentage of stool samples positive for the presence of eggs and the orange bar represents the percentage of negative stool samples.


The box-plot shows the results obtained in the White Merino and Black Merino sheep. The horizontal line dividing the box indicates the median value of eggs per gram of faeces (OPG) observed, the lower line the minimum value, and the upper line the maximum value. Outliers are represented by a circle.