Cattle blood parasite found in Victoria
The Department of Environment and Primary Industries (DEPI) is advising cattle producers in North East Victoria and Gippsland to be aware of the recent increase of theileriosis (T. buffeli) cases. DEPI District Veterinary Officer Lee Manning said while theileria was common in northern NSW and Queensland, and that cattle there had developed immunity and didn't show any illness, it had rarely been seen in Victoria.
"Theileria is a blood parasite, which typically infects cattle through a tick bite," Dr Manning said. "Victorian beef and dairy herds have been infected when cattle from the northern states, carrying ticks infested with theileria, are introduced into a herd or on to adjoining properties.
"The parasite can cause illness and even death to cattle that have not previously been exposed to theileria. Theileria is transmitted by blood-sucking ticks, including the common bush tick, which is widespread in Victoria. It can be carried by all mammals, including wildlife,dogs and cats, as well as birds," Dr Manning said.
"The parasite can cause illness and even death to cattle that have not previously been exposed to theileria. Theileria is transmitted by blood-sucking ticks, including the common bush tick, which is widespread in Victoria. It can be carried by all mammals, including wildlife, dogs and cats, as well as birds," Dr Manning said.
Other instances where blood may be transmitted between cattle, including blood sucking insects, needles, ear notching and castration, could also potentially transmit theileria. Dr Manning said there was no specific treatment for theileriosis; only symptomatic treatment could be provided, including good nursing, but cattle with severe anaemia may not recover.
"The disease causes mild to severe anaemia due to destruction of red blood cells and this can be seen as lethargy, weakness, pale mucous membranes, a drop in milk production, going off feed, difficulty breathing, abortions, jaundice and sudden death," she said.
"Cattle are more likely to show signs when stressed, especially at the point of calving but most infected cattle will have benign theileriosis and show no signs of illness."
Bush ticks are almost impossible to eradicate from a property because they are on and off the host in a week and live in pasture for many months, as well as surviving on wildlife.
"This parasite is not T. parva, which is an exotic parasite causing East Coast Fever in Africa. It is endemic in northern Australia, although rarely diagnosed in Victoria."
Contact your local veterinarian for advice if your cattle are showing multiple abortions, signs of anaemia or any other unusual signs. The disease can be confirmed by laboratory testing.
For more information, contact your local veterinarian or local DEPI Animal Health staff or call the DEPI hot line on 136 186.