Theileria rates a worry as gypsy day approaches
in the number of reported cases of cattle with theileria has prompted a warning for farmers to check stock for signs of the disease.
The number of diagnosed cases rose from 495 on March 19 to 547 on April 16, according to new data from the Ministry for Primary Industries.
Most of the cases reported are from dairy farms but there was also an increase in the number reported in beef-farming enterprises.
The location of cases remained in Auckland, Waikato and Bay of Plenty. Theileriosis had a big impact on farms last spring when more than 350 cases were confirmed.
The disease causes anaemia in cows and is spread by ticks, DairyNZ chief scientist Dr Eric Hillerton said.
There was now a heightened risk because of autumn calving, stock movements and recent rain.
‘‘During calving, cows’ immune systems and energy requirements change as they transition to milking and it makes their immune system less efficient and the cows more susceptible to infection,’’ Hillerton said.
Tick activity would increase, so farmers needed to check cattle and talk to their vet about treatment options if they found ticks, he said.
‘‘With stock moving offfarm to winter grazing and gypsy day [when farms traditionally change hands] looming, there is increased risk of theileriosis spreading to uninfected cattle.’’
Stock movement is the most important factor in managing the spread of theileriosis, as infected animals take it to a new location or are introduced to healthy animals.
‘‘The best way to minimise the risk of infection is by good biosecurity, including stock management and applying tick control when necessary, especially if moving cattle off-farm or purchasing new cows.’’
Signs of theileriosis included lethargy, pale mucous membranes, exercise intolerance, and increased respiratory and heart rates.
‘‘Farmers may notice animals lagging behind the mob when being shifted or lying down in the paddock. The animals are also likely to be off their food and appear hollow-sided,’’ Hillerton said.
‘‘Cows with theileriosis should be given rest, highquality feed and water, and be handled only when absolutely necessary. Farmers should also contact their veterinarian for advice.’’
Hillerton is speaking about theileriosis at a workshop at the DairyNZ Farmers’ Forum in Hamilton on May 7 and 8.