The Department of Primary Industries (DPI) is advising producers of the possibility of copper poisoning or ‘yellows' in livestock

The Department of Primary Industries (DPI) is advising producers of the possibility of copper poisoning or ‘yellows' in livestock, especially sheep, during the coming season.

DPI District Veterinary Officer Dr Chris Wernert said that the toxic plant heliotrope has been present in unusually large quantities in northern Victoria in the past few summers.

Heliotrope contains toxins known as pyrrolizidine alkaloid which alters the liver's metabolism causing the liver to hold abnormally high levels of copper.

"The liver damage caused by digesting heliotrope is cumulative, in other words, the liver damage increases each time the animal consumes heliotrope,' Dr Wernert said.

"When the liver becomes saturated with copper there is a rapid release of copper leading to kidney failure and death."

"Yellows' usually does not occur until sheep have been exposed to heliotrope for more than one summer and often occurs after the exposure to heliotrope has gone, when sheep are later put on lush pastures, which is rich in copper such as clover.

Dr Werner said the lush pastures that are present in spring were most likely to lead to the condition.

"Sheep are primarily affected since they are most often grazed in the locations where heliotrope is commonly found," he said.

"British breed and cross bred sheep are more commonly affected than merinos due to their different grazing habits.

"Other livestock such as cattle and horses are also susceptible to the effects of heliotrope but unlike sheep the liver damage associated with heliotrope poisoning and large losses of stock rarely occurs."

A homemade drench containing molybdenum can be made to prevent copper poisoning.

For the formula and guidelines or for further advice please contact your local veterinarian or DPI Veterinary or Animal Health Officer, or in NSW your Livestock Health and Pest Authority.