Haemonchus contortus or more commonly known as the barber’s pole worm is PGE-causing roundworm.

Whilst less common than other roundworms in the UK it is an important consideration during the grazing season.

The mature female worms can produce huge numbers of eggs (up to 10,000 per worm per day) meaning pasture build-up can be very rapid.

Haemonchus feed on blood with a single worm may consume up to 0.05ml of blood per day. Therefore, build-up of heavy infections can result in sudden and severe disease without any warning affecting both lambs and ewes. Its symptons can often be confused with liver fluke/fasciolosis.

Signs of disease:

Acute onset with anaemia and general fatigue.

Oedema or fluid accumulation (including bottle jaw).

Sudden death in heavy infections.

Haemonchosis does not usually present with diarrhoea.

Chronic infections may also occur, characterised by progressive weight loss, anaemia and loss of appetite.


Post-mortem in cases of sudden death associated with severe outbreaks.

Worm egg counts. These are generally very high and can be differentiated from other species of intestinal roundworm through specialist techniques.

Haemonchosis can be treated with most anthelmintic products, although some evidence of resistance to white drenches (1-BZ) has been reported in the UK. Some flukicidal products, such as nitroxynil and closantel are also effective against Haemonchus contortus and should be considered in certain cases.

For more information please speak to your vet or SQP.


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