Changes

== Introduction  ==

== Introduction  ==

''[[Haemonchus contortus]]'' is a tropical and sub tropical parasite of the abomasum, that may cause problems in temperate regions. It is around 2 cm long and has a 'barbers pole' appearance. It is a blood-sucking nematode and hence, clinical signs may be quite severe. Together with ''[[Ostertagia]]'', ''[[Nematodirus]]'' and ''[[:Category:Trichostrongyloidea|Trichostrongylus]]'' it makes up the [[Parasitis Gastroenteritis|parasitic gastroenteritis]] complex in sheep.

''[[Haemonchus contortus]]'' is a tropical and sub tropical parasite of the abomasum, that may cause problems in temperate regions. It is around 2 cm long and has a 'barbers pole' appearance. It is a blood-sucking nematode and hence, clinical signs may be quite severe. Together with ''[[Ostertagia]]'', ''[[Nematodirus]]'' and ''[[:Category:Trichostrongyloidea|Trichostrongylus]]'' it makes up the [[Parasitic Gastroenteritis|parasitic gastroenteritis]] complex in sheep.

''Haemonchus'' has a high biotic potential and egg to L3 development occurs very fast in hot humid conditions. In '''tropical and sub-tropical areas''', disease outbreaks depend on local rainfall. The parasite survives prolonged dry periods by arrested development which is resumed just prior to rainy season e.g. Australia, Brazil, Middle East and Nigeria. Arrested development is less common in areas with more frequent rainfall e.g. East Africa. There are several cycles of infection annually.

''Haemonchus'' has a high biotic potential and egg to L3 development occurs very fast in hot humid conditions. In '''tropical and sub-tropical areas''', disease outbreaks depend on local rainfall. The parasite survives prolonged dry periods by arrested development which is resumed just prior to rainy season e.g. Australia, Brazil, Middle East and Nigeria. Arrested development is less common in areas with more frequent rainfall e.g. East Africa. There are several cycles of infection annually.