Beware of high worm counts

The recent summer rains and hot temperatures make the conditions ripe for Barber's pole worm (Haemonchus contortus) to flourish in Victoria this summer.

Agriculture Victoria senior veterinary officer Dr Robert Suter said Barber’s pole worm is the most significant parasite of sheep in the summer rainfall areas of Australia.

“The adult female worms are prolific egg producers, leading rapidly to a heavy pasture contamination,” Dr Suter said.

“During warm, moist conditions, similar to what we have been experiencing, these eggs hatch into larvae and are eaten by sheep while grazing.

“Adult Barber’s pole worms live in the abomasum, the fourth stomach, of sheep.

“The worm gets its name because wound around the worm’s gut is the white ovary, packed with hundreds of eggs, and the gut of the worm is red, as it is full of blood.

This red and white spiral effect gives the worm its name as it looks like the classic barber’s pole.”

Like other internal parasites, Barber’s pole worms mainly affect weaners and lactating ewes.

Dr Suter said Barber’s pole worms feed by sucking blood leading to anaemia and ‘bottle jaw’, but not necessarily weight loss or diarrhoea.

“Just 1000 adult Barber’s Pole worms can remove 50ml of blood from a sheep per day.

“Consequently, Barber’s pole worm outbreaks can lead to high mortalities in a short space of time.”

He said the best way to be sure worm control programs are working is to conduct faecal egg counts.

“As with other internal parasites, drench resistance to Barber’s pole worm is becoming increasingly common,” he said.