Rising haemonchus cases in sheep
Haemonchus, also known as Barber’s Pole worm, is a gastroitenstinal infection in sheep, caused by the parasite Haemonchus contortus. The worm lives within the abomasum of the affected sheep and feeds on blood through the stomach wall. Each worm can ingest up to 0.5ml/day of blood, so an animal with 5,000 worms may lose 250ml of blood daily. Any age sheep can be affected and the severity of clinical signs depends on how many infective larvae have been ingested by each individual animal.
Clinical symptoms:
Ingestion of large numbers of infective larvae over a short period of time causes acute disease, symptoms include:
- Severe anemia
- Lethargy
- Weakness
- Some animals will collapse
- Some cases will end in death if not caught and treated
Ingestion of smaller numbers of infective larvae over several weeks to months causes less severe symptoms which include:
- A general loss to body condition progressing to emaciation
- Moderate anemia
- Bottle jaw (fluid build up under the jaw)
- Diarrhoea is not a symptom of this infection
Areas at risk
Sheep in warm, high rainfall environments are at greatest risk of infection as the parasite thrives in warm and wet conditions. Unfortunately, the worm is also adapting to climate change and can now survive a wider range of temperatures.
Haemonchus lifecycle
The Haemonchus contortus life cycle is a continuous cycle in warm and wet conditions.
- Larvae develop to mature worms in the infected animals stomach lining or intestines, adult female worms then lay up to 5,000 eggs daily
- The eggs then pass in the animals faeces
- The eggs hatch on the ground and free living larvae develop
- The free living larvae develop and migrate up blades of grass
- Grazing sheep then ingest the infective larvae and the cycle repeats itself
Treatment and prevention
- Regular worm egg counts should be carried out to asses worm burden. Haemonchus usually presents with exceptionally high worm egg counts
- Regularly body condition score or weigh animals to identify weight loss as early as possible
- Asses for anaemia by examining the colour of the eye membrane. This should be carried out regularly in flocks if the farm is known to be at risk
- Worm and quarantine incoming animals to prevent introducing Haemonchus to the farm
Haemonchus can be treated with most broad-spectrum wormers, as well as many narrow spectrum products which contain Closantel. Discuss your options further with a vet or qualified adviser.
How Herdwatch can help:
1.Body condition and record weights through the app – easily record body condition scores and weights in real-time, allowing for the early identification of health issues such as Haemonchus contortus. Regular tracking in the app helps you spot sudden weight loss or change in body condition, which are early indicators of parasite infestation. This allows timely intervention to minimise health impacts on your flock.
2. Medicine records made easy – Keep on top of all medicine purchases, treatments and inventory at the press of a button. See what animals have been treated and when to help minimise Haemonchus risk.
3. Pasture management in your palm – Map your farm in the app, colour coordinate fields by crop, and assign field notes. This can include simple notes to identify fields which have the perfect conditions for Haemonchus larvae to thrive.