Facial Eczema (FE) is a disease of ruminants caused by ingesting the spores of the fungus, P. Chartarum.
Despite a rather unfortunate name, Facial Eczema is primarily a disease of the LIVER, not just the skin (or face). Although the classical images of burnt teats and cows with skin sloughing off their back are often what first springs to mind when we talk about FE, these signs are actually the result of damage to the liver caused by toxins in the spores.
How does liver damage cause sunburn?
When the liver is damaged, it can no longer correctly process the chlorophyll in grass. The unprocessed break-down products of chlorophyll are “photodynamic”, which means they react with sunlight. These substances are released into circulation, and react with sunlight in areas of skin that are not shaded by dark pigmentation (white haired areas, white teats etc) causing a sunburn-like skin trauma known as “photosensitisation”.
Although you may only see photosensitisation in animals that have white areas of skin, liver damage caused by the toxin in the spores can occur in any animal, black or white- All animals have livers! In fact, it has been shown that 80% of animals with liver damage do not show any external skin signs.
Therefore, the cows with the sloughing skin are the tip of the iceberg.
Facial eczema has no cure – Prevention is key. Talk to your vet to work out a farm specific FE management plan and make sure your cows are getting the best protection possible.