A Naracoorte veterinarian says some sheep locally are suffering from sunburn because of their diet.
Photosensitisation is a skin condition which occurs when livestock eat a toxic plant. The toxins make their skin more sensitive to sunlight.
Livestock vet Tony Tully says the condition, mainly caused by a fungi that grows on grass, normally occurs in hot and humid conditions.
"We saw it right through winter which is very, very unusual.
"I've never seen photosensitization in my 20 years through winter, so it makes you wonder about global warming.
"It must have been mild enough for that fungi to grow, because we saw it right through our area, not just on one farm but on a number of farms and a number of different livestock enterprises."
© ABC 2013
16:51 EDT A lot has been said about struggling southern Mallee grain crops.