Warm humid weather is typically a sign that facial eczema could be lurking around the corner.
Facial eczema is caused by a toxin (sporisdesim) produced by the spores of the fungus Pithomyces chartarum growing on pasture. The fungus grows in the dead litter at the base of pasture in warm moist conditions. Sporisdesim, when ingested by cattle, damages the liver and bile ducts.
The damaged liver cannot rid the body of wastes and a breakdown product of chlorophyll builds up in the blood causing sensitivity to sunlight, which in turn causes inflammation of the skin.
Signs of facial eczema include a drop in milk production and growth rates, animals are restless, seeking shade and licking themselves, their exposed unpigmented or thin skin reddens, thickens and peels.
There is no cure for FE so prevention is the only way of protecting animals. To be effective, preventative measures will be in place before eczema spores are found. These measures include monitoring pasture spore count and either dosing animals with zinc or spraying pastures with a fungicide. Breeding cows that are more tolerant to facial eczema is a solution to reduce the impact from facial eczema in the long term.
