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Home Roundworms of Sheep and Goats Barber’s Pole Worm in Sheep and Goats

Barber’s Pole Worm in Sheep and Goats

(Haemonchus contortus)

Barber’s pole worm is most commonly found in Queensland and the northern half of NSW where summer rainfall is common or dominant. This worm is less of a problem in the winter rainfall areas of Australia, but localised pockets exist in all states and infections are worse in summers that are wetter than usual. It is a blood sucking parasite and can be fatal for all classes of sheep and goats.

Image: The classic “barber’s pole” look in female worms where the white reproductive tract twines around the pink intestine . Source: Deb Maxwell.

The adult female worms are quite long (20 to 30mm) and clearly visible. They have the characteristic ‘barber’s pole’ appearance due to the pink (blood-filled) intestinal tract of the worm twisted around the paler reproductive tract. The males are smaller (around 15mm) and pale pink. Females are prolific egg layers, laying up to 10,000 eggs per day, and as such, much higher worm egg counts are usually seen with these worms than with the scour worms. This also means that the level of worm egg count at which drenching should occur is higher.

Adults can become arrested or inhibited inside the sheep or goat for varying periods. They resume activity when external environmental conditions become more favourable, for example, at the onset of spring, or when ewes and does have lowered resistance to worms, which happens around lambing and kidding and until eight weeks after parturition. Even moderate infections of barber’s pole worm can have a marked effect on milk production of ewes and does leading to a retardation of growth in their lambs and kids.

Further ecological information on worms and their control:

Image: Barber’s pole worm (Source: Professor Nick Sangster, University of Sydney)
Image: Lancet on barber’s pole worm head (Source: J.A. van Wyk, Faculty of Veterinary Science, University of Pretoria & Onderstepoort Veterinary Institute, South Africa)


Abomasum (the ‘fourth stomach’).


Anaemia, lethargy and collapse, failure to gain weight and bottle jaw (sub-mandibular oedema). A break in the wool may also occur in acute outbreaks when stock become critically anaemic. Death can occur especially when disease onset in rapid.

In chronic disease, decreased food intake, weight loss and anaemia are commonly observed.

Signs of worms in sheep and goats

Image: Bottle jaw in sheep (Source: Dr R Woodgate, Department of Agriculture Western Australia)


The only accurate way to diagnose worm infections before productivity losses have occurred is to regularly conduct a WormTest (worm egg count). A larval culture is usually also recommended. The results allow you to make the best choice of drench for the situation.

Visual signs of infection only occur after significant blood (and therefore production loss) has already occurred. These signs can also occur with other parasites and diseases.


There are many options to treat for this worm and your choice will depend on:

  • the current size of the burden of this worm
  • which other worms are also present and in what proportion
  • which drenches are effective on your property and the length of protection you are seeking
  • the likely worm-risk over the next few months
  • the likely level of worm contamination on your pastures
  • the class of sheep or goat affected and their susceptibility to worms
  • the last drench group/s you used on this (and other) mobs
  • the time until these sheep or goats are sold/slaughtered and the withholding period and export slaughter interval of drenches you might use

Your decision can be assisted by using the Drench Decision Guide a simple tool that considers some of the points above.

You can also review the pages under the ‘Treat’ tab on this site to find out general information about drenches, including drench groups and actives, length of protection, which worms they treat, withholding periods, export slaughter interval and manufacturer. This information is also searchable for specific drenches using the ParaBoss Products Search Tool.

Note: only a few drench types are registered for use in goats.

The negative impact of this worm can also be reduced through browsing and grazing management strategies and by using one of the integrated Paraboss worm control programs that have been developed for different regions across Australia.

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