Facial Eczema

Facial Eczema (FE) is caused by spores of a fungus growing on the litter in the base of the sward. They release a toxin which attacks the liver. It is a serious disease that affects sheep and cattle and can be fatal.

Your losses are much greater than they appear. FE, when no symptoms are visible, can reduce lifetime productivity by up to 25%. There are practical ways in which you can reduce your losses. You should use two or three methods together. Breeding for increased tolerance to FE should be your first line of defence. Buying FE-tolerant rams will make a great difference in only a few years, but you have to be consistent in only bringing tolerant rams into your flock.

You can give all or part of your flock a zinc bolus, which lasts six weeks, or dose with zinc oxide weekly or fortnightly to reduce liver damage. For large numbers, you can spray zinc on pasture. Quit stock early, build up feed reserves, and aim for light rotational grazing.

Most vet clinics have a spore counting service. If one is not available, get together with other farmers and organise a spore counting service (persuade your vet clinic to offer the service, hire someone to do the counts). Spore counts will help you identify the safer parts of the farm (the shady, windy places). Fungicide sprayed before the onset of FE season will reduce spore counts for five to six weeks. Use these pastures for your replacement ewe lambs and hoggets. Aim to be lightly stocked through the danger period.

The symptoms of FE are distressing:

  • Frequent urination

  • Exposed areas develop a weeping dermatitis and scabby skin, affected areas may become infected or fly blown.

  • Avoiding direct sunlight, then drooping and reddened ears and swollen eyes.

  • Restlessness followed by shaking and rubbing heads against posts and gates

Not all animals with FE damaged livers will show these clinical symptoms—in fact, except in very severe outbreaks, most animals with FE liver damage will show no outward signs at all. A blood test—the GGT test—can be used to detect liver damage in these animals. Even low exposure to FE in young animals (sheep or cattle) seems to affect growth rate and longevity.

Don’t relax precautions too soon—a few cool nights or heavy rain doesn’t mean danger has passed. Once spore counts rise, pastures remain toxic until the spores disappear. Faecal spore counting offers a method of determining how much challenge has occurred to the animals.

Breeding animals for FE tolerance is a medium to long term strategy that:

  • Underpins other protective measures.

  • Can achieve significant tolerance in 5-10 years if
    managed well.

  • Requires consistent use of rams bred from tested and
    certified sires, from breeders such as Arahura Sheep Genetics.