A farm in Co. Wexford has seen its flock of sheep struck with a worm infection, which they are managing right before the upcoming breeding season.

A haemonchus contortus, or barber’s pole worm infection developed at Keane’s farm in Davidstown, Enniscorthy, and has affected both adult sheep and lambs.

This is a type of stomach worm that is becoming more common on Irish sheep farms in recent years, according to Michael Gottstein of Teagasc.

Barber’s pole worm

Barber’s pole worm is a gastrointestinal worm infection of sheep and goats in regions where conditions of high humidity coincide with high temperature.

The lifecycle of the worm consists of the larvae of barber’s pole worm, hatching and maturing in faeces on the ground before migrating to fresh grass for intake by grazing animals.

This migration requires warm, moist conditions, and the larvae are quite susceptible to dryness and low temperatures.

Gottstein explains that barber’s pole worm is somewhat different from the ‘normal’ stomach worms that we see during the grazing season because:

  • It affects both lambs and adult sheep – sheep don’t develop immunity unlike with other stomach worms;
  • It is a blood-sucking worm, so often the conditions are more like liver fluke (bottle jaw and anaemia);
  • It is a very prolific egg layer and egg counts are in the thousands rather than hundreds.

“The big problem with haemonchus contortus infection is the speed at which it developed,” Gottstein said.

“Lambs went from having a zero worm egg count in the faeces to having 15 dead lambs one month later.”

The egg count of one of the lambs submitted to the local regional veterinary laboratory for post mortem examination was 21,500 eggs/g.

Gottstein said that all sheep on the Keane farm have been treated with a closantel-based anthelmintic and that faecal egg counts will be monitored fortnightly for the remainder of the grazing season.

Flock condition

Keane’s sheep flock consists of 200 ewes, which are predominately Suffolk and Belclare crosses.

At this stage, only a small number of lambs have been drafted off grass, but Gottstein said the remaining lambs are on good grass, are receiving some concentrate feed and are improving rapidly.

The ewe flock has also been prioritised after the haemonchus infection and are on good grass to aid in the recovery of body condition.