Facial Eczema in Sheep

Written by Bas van Luijk - Veterinarian, East Coast Farm Vets

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Facial eczema, a common and persistent issue in farming, poses significant challenges for farmers and can have severe consequences on sheep health and productivity.

Facial eczema is primarily caused by the consumption of spores produced by the Pithomyces fungus, which thrives on pasture during warm and humid conditions.

New Zealand's temperate climate, with its high rainfall and warm temperatures, creates an ideal environment to produce this fungus.

During late summer and early autumn, when the pasture is at its driest and spore counts peak, sheep are particularly vulnerable to ingesting the toxic spores.

The effects of facial eczema in sheep are mostly visible on the face, ears, and wool-free areas of the body.

 Affected sheep can show signs of discomfort, such as excessive itching, rubbing, and the development of lesions on their skin.

In severe cases, facial swelling, loss of wool, and even liver damage can occur, leading to reduced weight gain and lower reproductive performance.

To effectively manage facial eczema, farmers can employ various preventive measures:

• Monitoring spore counts in pasture is a crucial aspect of prevention. Regularly testing for spore levels allows you to identify high-risk paddocks.

• Move sheep to paddocks with lower spore levels or use supplementary feed to reduce their reliance on contaminated pasture.

• Identify and remove affected sheep from pastures with high spore counts. Adjust grazing practices to ensure high-contamination pastures are not grazed during high-risk periods.

• Ensure any affected animals have access to shelter and shade to minimise sun exposure as sunlight exacerbates the effects of facial eczema. Application of a topical zinc ointment will provide protection from the sun while encouraging healing of any wounds.

• Use pasture covers and strategic use of fungicides to minimize exposure to toxic spores.

• Supplement with zinc during high-risk periods as zinc helps detoxify the liver and reduces the severity of clinical signs in affected sheep. Zinc can be administered through pasture supplementation, feed additives, oral drenching, or boluses.

• Selective breeding for resistance to facial eczema is another long-term strategy. Some sheep breeds exhibit a higher tolerance to the condition, and by selectively breeding for resistance, you can gradually reduce the prevalence of facial eczema in flocks.

Facial eczema requires a comprehensive approach for effective management and prevention.

With careful monitoring, strategic pasture management, and the incorporation of preventive measures such as zinc supplementation and selective breeding, we can minimize the impact of facial eczema and maintain the overall herd health and productivity.

This article was published in the Gisborne Herald on 25/01/25.