MPI reiterates anaemia warning

While most cases are in the northern half of the North Island, some are reported further south, including one at Rangiora, Canterbury.

Since the ikeda strain was first identified in Northland just over a year ago, 124 farms have confirmed outbreaks with the autumn drought, mild winter, and now growthy spring causing a spike in cases, thought to be due to greater tick survival and spread.

MPI acting director general Scott Gallacher says it is important farmers are aware of the situation to minimise impacts on herds and livelihoods.

Signs of anaemia include lethargy, pale skin around genitals and udders, and increased respiratory and heart rates. Stress and movement of affected animals should be minimised, as reduced capacity to transport oxygen around the body can lead to collapse and death.

Some infected animals may show no signs of illness as they are immune, following previous exposure, but the ikeda strain is thought to be overcoming immunity as it is different from the strain which has been in New Zealand for at least 30 years. Symptoms are also more likely where animals are stressed, such as at calving or by other infections. 

“Anyone noticing this kind of general illness in their cattle should contact their veterinarian in the first instance,” says Gallacher. “Veterinarians can provide advice on how to manage ticks and help prevent further cases.  Vets and pathologists with test results identifying Theileria should report cases to MPI on 0800 80 99 66.”

MPI says it is working with the animal industry bodies and the New Zealand Veterinary Association (NZVA) to determine the scale of the situation, build knowledge, inform farmers and carry out research into effective management of the disease.

Most cases to date have been in Northland, Waikato, King Country and Bay of Plenty but some in Whanganui, Taranaki, Reporoa and Rangiora (South Island) have also been confirmed.

DairyNZ put out a warning about the disease earlier this month.

“It’s been such a devastating spring in terms of tick numbers,” the levy-body’s chief scientist Eric Hillerton told Dairy News’ sister paper, Rural News.

Colleague John Bluett, an animal husbandry specialist with DairyNZ and a Waikato dairy farmer, said cases were happening “exponentially” in Waikato. “The weather and long grass have been ideal for the tick that carries it.”

Bluett’s advice was if you think your cattle might have it, get the vet in straight away and get a test done.

“These cows have to be nursed very gently. Give them plenty of high energy feed because they’ve not got the energy to go and get their own, and it will take them a while to recover.

“Some farms that have had quite a few cases have put them on once-a-day milking.”

Hillerton says keeping an eye-out for ticks around the tail-head, base of udder and inside the legs – “basically wherever the tick can get close to the skin” –  is a good idea, but warns they’re hard to spot as the immature forms are only the size of a pinhead, and even the adult is only 2.5mm across initially. “It grows to about the size of a pea before they drop off.”

Cattle movements, and possibly other animals including birds, spread the ticks.