Emerging cattle disease causes deaths

In recent months District Vets have confirmed theileriosis on a number of properties in the Hume LHPA.

Steve Whittaker, Hume LHPA Senior District Vet, warns that this disease, which has not been previously recorded in this area, has already caused deaths and illness in cattle on seven properties across the district.

"Theileria is a protozoan parasite that infects the red blood cells causing red blood cell destruction. This can cause serious disease including abortion in pregnant cattle and deaths. Affected cattle may appear dull with pale membranes (eyes and mouth) and often have difficulty breathing. Others are just found dead," he said.

"This is a disease that commonly occurs in coastal and northern NSW and in Queensland. It has not been recognised as a cause of disease in southern NSW cattle until recently."

Dr Whittaker says that with all the affected properties there was a link with agisted or purchased cattle from areas where the disease is commonly found.

"Strong current demand for store cattle means many producers are sourcing stock from outside the local area. There is a risk associated with introducing coastal cattle and I would suggest where possible avoiding introductions and agistment from these areas."

Helen McGregor, Hume LHPA district vet based in Wagga Wagga, is coordinating local research efforts to better understand the nature of this disease in local herds.
 
"A vector is required to transfer parasites in the red blood cells between animals. This occurs when the vector, commonly a tick, bites an infected animal and subsequently bites a non infected animal transferring parasitised red blood cells in the process," she said.

"It is possible that there may be more than one species of tick (or other blood sucking vectors) involved in the transmission. The tick vector may also be surviving in the environment due to unseasonal rainfall and lower than average temperatures for the time of year."

"Unfortunately there is no specific treatment available in Australia for Theileria in cattle. Tick treatments are unlikely to be successful in preventing all transmissions as the ticks spend a great deal of time off the animal and the treatment only works against the ticks when they are on the cattle."

"Further complicating treatment is the possibility that there are a number of tick species involved in the transmission and the fact that some tick species may be able to survive for up to 12 months in the environment without contact with cattle."

Producers are asked to closely monitor their cattle and notify either their local LHPA vet or private vet if they suspect this disease is occurring in their herds.

Media contact: Kylie Dunn 6391 3720 / 0428 465 378