Large Roundworm

Mainly found in foals and young horses, as horses develop natural immunity to this parasite by about 18 months of age.

Size/appearance

The large roundworm can be up to 40cm in length and is white in colour.

Location in horse

The larvae migrate through the bloodstream to the liver and the lungs. These get coughed up and swallowed and return to the small intestine to develop into adults.

Symptoms

Symptoms include coughing, poor growth rate and a dull coat. Because of the worms size, they can cause a fatal blockage or rupture of the gut.