{"id":1532875,"date":"2025-07-15T12:37:07","date_gmt":"2025-07-15T10:37:07","guid":{"rendered":"https:\/\/laboklin.com\/haemonchus-contortus-in-small-ruminants-and-new-world-camelids\/"},"modified":"2025-08-13T12:50:54","modified_gmt":"2025-08-13T10:50:54","slug":"haemonchus-contortus-in-small-ruminants-and-new-world-camelids","status":"publish","type":"post","link":"https:\/\/laboklin.com\/ch-fr\/haemonchus-contortus-in-small-ruminants-and-new-world-camelids\/","title":{"rendered":"Haemonchus contortus in Small Ruminants and New World Camelids"},"content":{"rendered":"

[vc_row][vc_column width=”2\/3″][vc_column_text css=””]Haemonchus contortus<\/em>, commonly known as the red or twisted stomach worm, is a parasitic nematode belonging to the family Trichostrongylidae. It is one of the most significant gastrointestinal parasites of ruminants, particularly affecting sheep and goats. In recent years, it has also become increasingly prevalent in New World camelids, where it can likewise cause serious health issues. As a blood-feeding parasite, it can induce severe anaemia, which may lead to ruminal stasis and even death.<\/p>\n

Due to its high pathogenicity, rapid development cycle, and growing resistance to anthelmintic treatments, Haemonchus contortus presents a major challenge in the management of both ruminants and New World camelids. In the original habitat of New World camelids – the high, arid regions of the Andes – Haemonchus contortus is only sporadically found. In contrast, the warmer and more humid climate of Central Europe offers more favourable conditions for the development and reproduction of the larvae. As a result, pasture-based husbandry systems, which are the most common form of keeping New World camelids in Germany, can lead to significant pasture contamination and infection pressure.<\/p>\n

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Morphology and Life Cycle<\/h2>\n

Adult worms measure approximately 10\u201316 mm in males and 20\u201330 mm in females. They parasitise the mucosa of the abomasum in ruminants or the third compartment of the stomach (C3) in New World camelids. Using a tooth-like structure in their buccal region, adult worms rupture small blood vessels in the gastric mucosa and feed on the host\u2019s blood. The presence of blood in the worm\u2019s intestine gives the females their characteristic red-and-white striped appearance, as the dark red intestine spirals around the paler uterus filled with thousands of eggs.<\/p>\n

Each female can lay up to 5,000 eggs per day, which are excreted in the host\u2019s faeces. Larval development is fastest under warm and moist conditions (20\u201325\u202f\u00b0C): L1 larvae hatch within 1\u20132 days then moult into L2 and subsequently develop into infective L3 larvae within about one week. The L3 stage is highly resistant to environmental stressors and can survive lower temperatures. In moist environments, L3 larvae can actively ascend blades of grass and are ingested by the host during grazing. After ingestion, the larvae migrate to the crypts of the abomasal (or C3) mucosa, where they develop into L4 and then into adult worms. The cycle continues as these adults begin to produce eggs, which are again shed in faeces. The entire life cycle typically takes 3\u20135 weeks and can repeat several times per year.<\/p>\n

Under warm and humid conditions, H. contortus populations in a herd or pasture can increase exponentially. The resilient L3 stage can survive mild winters on pasture, contributing to reinfection in spring. Additionally, within the host, L4 larvae or adult worms can enter a state of arrested development (hypobiosis). This occurs in autumn, and development resumes at the end of winter, leading to heavy pasture contamination early in the grazing season. This so-called “spring rise” in egg shedding is further exacerbated in females by the periparturient egg rise, a physiological phenomenon linked to weakened immunity during pregnancy, parturition, and lactation. As a result, pastures can become heavily contaminated within a short period, exposing young animals to high infection pressure from birth.[\/vc_column_text][\/vc_column][vc_column width=”1\/3″][vc_column_text css=””]<\/p>\n\n\t\t\t