Haemonchus contortus

Haemonchus contortus, also known as the <a href="/facts/Barber%2527s_pole/fdlKMxTt">barber's pole</a> worm, is a very common parasite and one of the most pathogenic <a href="/facts/Nematode/yLMJ43Eu">nematodes</a> of <a href="/facts/Ruminant/tTcBMxk4">ruminants</a>. Adult worms attach to <a href="/facts/Abomasum/4UScp81n">abomasal</a> mucosa and feed on the blood. This parasite is responsible for <a href="/facts/Anemia/AgEPPmg8">anemia</a>, <a href="/facts/Oedema/Q6MI3KdH">oedema</a>, and death of infected <a href="/facts/Sheep/cjkJyI4f">sheep</a> and <a href="/facts/Goats/BrsPJmdX">goats</a>, mainly during summer in warm, humid climates.
Females may lay over 10,000 eggs a day, which pass from the host animal in the <a href="/facts/Faeces/r9HDKB8G">faeces</a>. After hatching from their eggs, H. contortus <a href="/facts/Larva/GKo2FIew">larvae</a> <a href="/facts/Ecdysis/P4SN14xI">molt</a> several times, resulting in an L3 form that is <a href="/facts/Infection/182XrncP">infectious</a> for the animals. The host ingests these larvae when grazing. The L4 larvae, formed after another molt, and adult worms suck blood in the abomasum of the animal, potentially giving rise to anaemia and oedema, which eventually can lead to death.
The infection, called haemonchosis, causes large economic losses for farmers around the world, especially for those living in warmer climates. <a href="/facts/Anthelminthics/2p02KN0X">Anthelminthics</a> are used to prevent and treat these, and other, worm infections, but <a href="/facts/Drug_resistance/cgLruXm6">resistance</a> of the <a href="/facts/Parasitism/HWPcgky7">parasites</a> against these <a href="/facts/Chemical_substance/EWcXU41d">chemicals</a> is growing. Some breeds, such as the <a href="/facts/West_African_Dwarf_goat/uuU5EUe8">West African Dwarf goat</a> and N'Dama cattle, are more resistant than other breeds to H. contortus (haemonchotolerance).

Haemonchus contortus open-in-new

Haemonchus contortus