Spring eczema is a catch all term for photosensitisation signs between August and December. Most likely candidates are plants and fungi. Culprit plants contain photodynamic agents that react with sunlight and damage skin cells (primary photosensitisation)
Fungi in feed tend to cause liver damage which reduces the liver’s ability to remove the agents which then reach the skin and again react with sunlight (secondary photosensitisation). In young calves with immature livers, added challenges are early weaning and consuming high levels of grass, parasites, bacteria, and ironically worm treatments.
Whilst the exact offender may not always be determined, note that Facial eczema and sporidesmin are not included as these typically occur in mid-summer to autumn.
Signs are redness and swelling in light coloured skin and hairless areas, usually with irritation and pain. Udders, heads, and white areas of the body are frequently affected. Animals generally seek shade, and/or mud and water to cool the inflamed skin. Then may follow reduced production and growth, and weight loss. Severe cases may develop jaundice and bottle jaw. In cows blood sampling for liver function will help determine if full recovery is likely. Damaged skin may be prone to flystrike, dermatophilosis and infection. Recovered skin may develop chronic thickening and scarring.
The case pictured here is a yearling heifer grazing in a mob of 80, and on new grass for the previous two weeks. No other cases were detected by the owners, and this animal was noticed the day before the vet visit. Initially from paddock observation, they assumed it was woody tongue. Upon drafting her, they noted she was drinking a lot, and grazing a little and the skin around the head looking red and sore.
Clinical examination revealed a raised temperature (39.4’C), moderate bottle jaw, mild weight loss, normal faeces and urine. Photosensitisation was worse around the head, including swollen muzzle and nostrils, and all eyelids. These areas were weeping and crusting. The vulva and perineum were inflamed but not cracking or weeping. Inside the mouth all membranes and tongue were normal. A presumed diagnosis of Spring Eczema was confirmed by liver enzyme analysis in the laboratory.
Treatment is supportive – removing the offending plants and liver toxins if identified; minimising direct sunlight (daytime housing in darkened sheds, grazing at night, sunblock cream, cover); pain relief, access to supplements in the daytime such as silage and hay.
In this case, the heifer has access to a large hay shed which she voluntarily uses during the day, and grazes mature pasture at night. She received antihistamine and anti-inflammatory injections for initial relief. The skin is steadily improving. The liver has good capacity for healing and enzyme levels generally return to normal over several weeks.