Haemonchosis (Haemonchus contortus)
Introduction
Haemonchosis is a severe gastrointestinal nematode infection of sheep and goats caused by Haemonchus contortus. It is commonly known as barber’s pole worm due to the appearance of the female worm filled with blood in the intestine.
Etiology
Causative Agent
Epidemiology
- Sheep and goats (most important)
- Warm, humid climates favor transmission
Pathogenesis
- Adult worms attach to abomasal mucosa
- Blood-feeding causes severe anemia
Clinical Signs
- Severe anemia (pale mucous membranes)
- Submandibular edema
- Weakness and death in heavy infections
Diagnosis
- Fecal egg counts
- Clinical anemia (FAMACHA system)
Treatment
- Benzimidazoles (resistance common)
- Macrocyclic lactones
Control
- Pasture rotation
- Selective deworming
- Breeding resistant animals
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