What is Facial Eczema (FE)?

The fungus Pithomyces chartarum releases spores in pasture, which produce a toxin known as sporidesmin. This toxin damages the liver.
The damaged liver cannot rid the body of wastes and a breakdown product of chlorophyll (plant part) builds up in the blood causing sensitivity to sunlight, which in turn causes inflammation of the skin.
The danger period is generally between January and May when we see grass temperatures above 12 degrees for two to three consecutive nights and high humidity.

Which animals are susceptible to FE?

Sheep, cattle and fallow deer are sensitive to FE.
Alpacas are incredibly sensitive and need very careful management to prevent ingestion.
Goats seem to be more resilient to FE; this is thought to be because they browse more, but they are still susceptible.
FE has not been reported in horses and pigs.

Clinical signs seen in affected animals

Sheep – the initial signs include restlessness, head shaking, and seeking shade. This progresses to drooping ears and swollen eyes and face. Skin may become reddened and then crusty and dark. It eventually peels off leaving large raw areas which are susceptible to infections and flystrike. Membranes become yellow and sheep lose their appetite and therefore lose weight rapidly. If severe enough sheep will die from this disease.

Cattle – the signs are similar to those mentioned in sheep. In dairy cattle the udder and teats are often severely infected. Signs can include weight loss or decreased weight gain and general sickness. As in sheep, death can occur months after the initial liver damage.

Alpacas – initial signs include irritation and restlessness. Skin swelling, crusting and oozing (often around nose and ear margins) are seen as in sheep and cattle. Decreased growth rates, abortion and sudden death are also common.

How to prevent FE

It’s crucial to remember there is no cure for FE. Liver damage caused by the toxin sporidesmin is irreversible. Prevention is the key. Multimodal prevention strategies include oral Zinc supplementation to help prevent liver damage at the animal level and pasture spraying to minimize fungal spore exposure.

Cattle and Sheep:

For most of you the easiest way to help prevent FE in your sheep and cattle is to use an intra-ruminal Zinc capsule. If you have inserted a capsule over the tongue and into the oesophagus before, you can do this yourself. Otherwise, ask your Vet to teach you how to do it safely.

Face-Guard, a Zinc bolus only available through Veterinarians, is used to manage FE. Two sizes are available for cattle, 90 – 250 kg or 251 – 660kg, and they prevent FE for up to 6 weeks. This can be extended to 10 weeks if a top up dose is given 6 weeks after the first treatment. Face-Guard boluses for sheep can be used to treat sheep 25kg and over.

Another intra-ruminal device available is Time Capsule. Time Capsules only prevent FE for four weeks in cattle and if they are dropped, the wax coating may get damaged. This can lead to Zinc overdosing and/or reduced efficacy.

Alpaca: Intraruminal Zinc capsules do not appear to be useful in alpacas as the outside coating is broken down very quickly, resulting in very rapid absorption of the Zinc, meaning it has a very short duration of effect.

Zinc oxide incorporated into feed is the easiest way to get alpacas to consume Zinc. You can sprinkle powder over feed or use pre-made pellets containing Zinc. Zinc tastes bitter so disguising it with molasses works well.

Alpacas normally won’t get enough Zinc to protect them from FE, therefore pasture management is very important

When to start zinc dosing

Spore count levels over 50 (‘ooo/g) are a concern; you want to be treating stock at least 2 weeks before the counts reach 90 -100 (‘ooo/g). For up to date spore counts you can sign up to our weekly text service or you can deliver your own pasture samples to your local Anexa FVC clinic to get them checked.

Pasture spraying and management:

The easiest way to stop the fungus growing is to kill the fungus off by spraying with a fungicide spray.
Fungicide spraying works best when there are minimal spores present, but when a period of rapid fungal growth is anticipated. The reason for this is that the spray kills the fungus, not the spores. The protection gained from spraying lasts approximately six to eight weeks.
It is important to realise that fungicide sprays for FE are only 60 to 70% effective, therefore additional protection is needed to protect your animals.
It is also important not to “top” paddocks during this period as this will allow the fungus to multiply in the dead pasture.

What happens if my animal gets FE?

The most effective treatment for affected animals is TLC (tender loving care). FE is a form of sunburn and getting the animals out of the sun provides relief and prevents further sun damage. Complete darkness is best such as a shed with the windows blacked out. Second best is shade and sunblock cream such as Filta Bac applied liberally to affected areas, and light covers. Supply plenty of feed such as hay (as a replacement to grass in the diet to reduce the numbers of spores being ingested) and high-energy supplements like molasses, silage, maize or meal. Oral Zinc treatments should be continued to enhance prevention.

Please contact your Vet if you have concerns as this condition is extremely painful for the animal.