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Barber's pole worm

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.

The worms are quite long (20 to 30 mm) and clearly visible. Only adult females have the characteristic ‘barber’s pole’ appearance due to the pink (blood-filled) intestinal tract of the worm twisted around the paler reproductive tract; whereas the males are smaller (around 15 mm) and pale pink. Females are prolific egg layers, laying up to 10,000 eggs per day, as such, higher worm egg counts are usually seen with these worms.

Adults can become arrested or inhibited inside the sheep for varying periods. They resume activity when environmental conditions become more favourable or when ewes have lowered resistance around lambing time.

Further ecological information on worms and their control:


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

Location

4th stomach or abomasum.


Signs

Death, anaemia, lethargy and collapse, failure to gain weight and bottle-jaw (sub-mandibular oedema). A break in the wool may also occur.


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

Diagnosis

The only accurate way to diagnose worm infections before productivity losses have occurred is to conduct a WormTest (worm egg count). A larval culture is usually recommended in areas where barber's pole worm are common and in other areas, under wetter than normal conditions, when barber's pole worm can become a problem. The results allow you to make the best choice of drench for the situation.

Visual signs only occur after significant production loss has already occurred. Also, these signs can occur with other parasites and diseases.


Treatment

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

  • the current burden of this worm
  • what other worms are also present and in what proportion
  • the drench-resistance status and which drenches are effective on your property
  • the likely worm-risk over the next few months and the length of protection you are seeking
  • the likely level of worm contamination on your pastures
  • the class of sheep and their susceptibility to worms
  • the last drench group/s you used on this (and other) mobs
  • the time until these sheep 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 Drench pages on this site to find out specific information about drenches, including their drench active, drench group, length of protection, which worms they treat, dose rate, withholding period, export slaughter interval and manufacturer.

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