Theileria Anaemia Diagnosed in Eltham (Nov 2013)
A few days ago Eltham Vet Services diagnosed its first case of Theileria orientalis (ikeda), the tick borne disease that causes a potentially fatal anaemia in cattle. This disease has spread down the country after being first diagnosed in 2011 in Northland. Since then it has taken hold of the upper north island & caused plenty of problems. The latest estimate from NZVA & MPI has 213 farms testing positive to the disease with close to 900 deaths as a result.
Cows present off their milk, lethargic & on closer examination are found to be profoundly anaemic (blood loss). This anaemia is caused by the disease destroying red blood cells, which the organism parasitizes. The Theileria organism is carried & transmitted by infected ticks
The disease is not spread by direct animal-to-animal contact in the absence of ticks. There are no human health or food safety risks associated with Theileria.
The hot, dry summer and mild winter experienced this year are thought to have allowed an increase in tick populations and early activity this spring.
In our area we have been watching this disease for a while wondering if and when we might be affected. Our biggest concern was with animals coming into our area either carrying infected ticks on them that could spread to the rest of the herd or simply coming in already infected, which could well be the case with the two cases diagnosed locally. We haven’t found any ticks on these cows and are hoping they will be one off cases (these cows had come from local sale yards but their actual origin is unclear). Outbreaks of Theileria have been noted in the Waverley & Waitotara region, where one property had 30 cases requiring blood transfusions.
The most dangerous times of the year for infections tend to be autumn & spring when ticks start to feed so control has been focussed on treating stock in high risk areas with a suitable tick product at those times of year. Things got so bad up north that all stocks of the most suitable product, Bayticol ran out earlier this year and more had to be rushed in from Australia. There is another product now available called Flumethrin, which is a copy of Bayticol & made in NZ. It has no milk or meat withholding period & costs around $3.50-$4.00 per dose for an average sized dairy cow.
Once diagnosed the only treatments for infected cows are blood transfusions (generally taking blood from another uninfected animal on the property & transfusing into the affected cow) and a product called Buparvaquone, which had to be rushed through the usual registration process to be used in NZ and targets the actual Theileria organism in the blood cells. The only problem with Buparvaquone is that it has a milk withholding period of 43 days and a meat withholding period of 18 months. Offal has a permanent withholding period so must be discarded. Animals treated with the anti-Theileria drug must be permanently tagged so they can be identified for the remainder of their lives, and registered as treated on the NAIT website. This has obvious ramifications for dairy farmers with regard to milk supply & for beef farmers trying to get animals to the works. Many farmers have chosen not to use this drug & rely on blood transfusions & the animal’s immune system to fight the disease.
So prevention is definitely better than cure.
In our situation, the farmer affected has since treated all his animals with Flumethrin to try & prevent any potential tick hopping within the herd & kill any ticks that may be present.
Our advice for anyone who is concerned about potential for ticks in their herd is to get in now and treat all animals on the property with Flumethrin (available now) or Bayticol (available again in 2 weeks) before ticks have a chance to get established on your property. This is especially relevant in drier areas south & east of Eltham where it can get very hot & dry over summer. Nearby deer farms or properties that were deer farms in the recent past have the potential to still harbour a viable tick population so you should consider the history of your farm & that of the neighbours.
If you see ticks (around here most ticks are still likely to be uninfected) on your cows don’t panic but get in and treat your animals as soon as you can & watch affected stock for signs of sickness related to anaemia: Going off milk, loss of body condition, slow & lethargic, very pale mucus membranes especially the vulva, gums & whites of the eyes. Look for any signs of yellowing as jaundice generally follows severe anaemia.
Historically farms on the ring plain in the Eltham area haven’t been affected much by ticks due to the climate here. Sheep & beef farms east of Eltham occasionally see ticks and properties susceptible to drought south of us have the potential for sustainable tick populations.
If you have stock coming home from areas where Theileria has been diagnosed or has the potential for viable tick populations, or have bulls coming from out of the region to run with the herd & heifers, insist that they are treated with Flumethrin or Bayticol before they are sent to your property. On arrival keep them separate for a week and observe them for signs of illness or ticks (look behind and in ears, between legs etc.) before introducing them to the rest of the herd.
If you have any concerns talk to one of us. If you decide to treat your stock with Bayticol or Flumethrin, please talk to John first so he can get more in stock; supplies are still in demand nationwide & stock-piling in relatively low risk areas like Eltham is being discouraged, so he’ll need a couple of days to get it in for you.
You can find more out about Theileria by visiting the DairyNZ website: http://www.dairynz.co.nz/animal/health-conditions/theileria/ or The Franklin Vets site here : www.franklinvets.co.nz & search for Theileria under the Dairy section
Testing times. By SUE O'DOWD - Taranaki Daily News
Dairy farmers are being urged to safeguard their herds against the devastating disease bovine viral diarrhoea (BVD).
Eltham Veterinary Services is offering tailor-made protection plans to about 100 farmers whose animals have no immunity to BVD and are most at risk of contracting it.
-Bovine viral diarrhoea, or BVD, occurs in cattle after close contact with infected animals.
-All body fluids contain the virus.
-BVD suppresses the immune system and causes fertility problems.
-BVD causes scouring, pneumonia and low growth in calves, which may be born deformed and weak.
-Calves born from infected cows may appear normal, but shed the virus in large amounts for their entire lives and are a major source of infection.
-Cows with BVD are prone to mastitis, their production falls, and their somatic cell counts rise.
Dr Polly Otterson and Dr Andrew Weir are promoting the message that bulls should be tested for BVD and vaccinated, although support from stock agents and bull sellers is guarded.
Dr Otterson said there was a long way to go to educate farmers about BVD, because of the prevalent view that "it won't happen to me".
Farmers needed to think now about testing and vaccinating, because cows were most vulnerable to pregnancy loss when bulls were introduced to the herd for mating, she said.
"Whether you have no BVD in the herd or heaps, it still pays to have the bull vaccinated.
"Testing and vaccinating every bull is a cheap way to give huge protection. Not having BVD is great, but if it comes into a vulnerable herd, it will hit it harder."
While fewer than 1 per cent of bulls were persistently infected (PI) - born with BVD - the consequences of a herd infection were devastating, she said.
"The PI bull is like a house fire. The risk is small, but when it does happen, it's hard to recover from."
Vaccination consists of two shots a month apart, with the second shot a month before mating. An annual booster is required. Bulls would need the second shot by the beginning of October to be protected.
Dr Otterson said most Taranaki bull suppliers tested for BVD, but vaccination was less common.
She described buying bulls from the saleyards or small operators as risky. A bull that tested negative for BVD but was not vaccinated could become infected at the saleyards, she said. She favoured proof of BVD tests and vaccinations.
"But there needs to be consumer demand for it, so that farmers will not buy bulls without certificates."
John Kelly, of John Kelly Livestock Ltd, said he supported bull testing and vaccination because he knew BVD could devastate farmers' lives. He had clients who had lost 20 to 30 per cent of their young stock - their replacement cattle - to BVD.
"I recommend to my clients that they insist on testing and vaccination."
He said he would like farmers to be better educated about the disease, because messages about it were inconsistent. He also believed professional graziers should require testing and vaccination before accepting cattle.
Bill Craig, of Stratford, who hires and sells bulls, said he tested and vaccinated for BVD because he had to. Of 1200 bulls he had just had tested, two returned positive tests and were culled.
This year Mr Craig lost eight to 10 calves after the virus occurred in his own Hereford herd.
Although bull seller John Washer, of Oakura, tests and vaccinates 500 Jersey bulls a year, at a cost of $20,000, he has never found a reactor.
"I have to wonder if I've been lucky, because I do know that people who have had BVD are decimated by it," he said.
While somewhat sceptical of BVD's incidence, he acknowledged that testing and vaccination were good insurance because of the disease's crippling effect on dairy herds.
When BVD was eradicated, vets would no doubt find something else they wanted bull sellers to test for, he said.
Hurleyville bull supplier Bernie Fowler said BVD testing was cheap insurance. He tested and vaccinated all his bulls because most buyers wanted proof.
"But it's down to the individual farmer to ensure the tests are done. If a farmer brings an animal on to his property, it's at his own risk."
Mr Fowler, who is wintering 450 bulls, said it was in his interest to be proactive in animal health.
Allied Farmers' dairying co- ordinator for Taranaki, Kim Harrison, said astute breeders already tested and vaccinated their bulls, but some traders were put off by the cost. Increasingly, dairy farmers were demanding that bulls they bought were tested and vaccinated.
Dr Otterson said Taranaki had the lowest prevalence of BVD in New Zealand, with 11 per cent of dairy herds with an active or recent infection, possibly because herds here were smaller and relatively isolated.
Figures published in 2007 put the cost of BVD to the dairy industry at $44 million.
An outbreak last season cost an Eltham farmer more than $12,000 per 100 cows. It was caused by a heifer born on the farm three years ago and was introduced to the herd in March last year, when the cows were pregnant.