It can be hard trying to focus on what we don’t see! For every clinical case of facial eczema (FE) there are 10 subclinical cases.

FE is caused by a fungus, pithomyces chartarum, which grows on dead pasture litter. In late summer and autumn, when periods of warm humid weather are common, the fungus can multiply rapidly producing large numbers of spores which contain a toxin called sporidesmin. 

When livestock ingest pasture with high spore loads, the toxin can cause severe liver damage and affect productivity and welfare.

Clinical (visible) signs:

• Restlessness

• Seeking shade

• Licking, itching, or rubbing

• Drop in production

• Redness, swelling, or peeling of unpigmented or thin skin

• Swollen drooping ears

• Shaking of the head and ears.

Subclinical signs:

• Reduced production (0.14–0.35 kg of milk solids per cow per day)

• Reduced growth rates

• Reduced fertility

• Weight loss

• Jaundice

• Liver damage.

Not all animals with FE show clinical symptoms, but liver damage can occur even when there are no visible signs. Damaged liver tissue from FE does not regenerate, and animals may develop chronic wasting or die months later. Blood tests can be used to monitor the extent of subclinical FE in individuals.

Even if you don’t see clinical signs amongst your herd, we recommend taking pasture samples to make a spore count and take action if necessary.

Oral supplementation of zinc is the best way to protect against FE. It helps inactivate the sporidesmin toxin so it does not damage the liver. Zinc can be given to cows through the water supply, mixed through feed, by drenching individual animals every day, or by a slow-release bolus (Face-Guard is recommended for youngstock).

Get in touch for help on how to strategically take pasture samples throughout the FE season and advice on how to best supplement zinc to the animals on your farm.