Bluetongue may be slipping from the minds of some
farmers, but those in the south east have been warned against
complacency
Bluetongue strain
eight (BTV8), despite the lack of cases in indigenous animals
last year, still poses a massive threat to UK livestock. Farmers
should plan their vaccination strategies with their vets
immediately to ensure protection against the disease.
Speaking at a Livestock Health South
East-organised bluetongue briefing at Ashford Market, Kent,
last week James Mulluneux of NFU south east said the disease was
still raging in Continental Europe and the discovery of new strains
of the disease there in recent months shouldn't distract UK farmers
from the challenge posed by BTV8. "This is still the strain which
poses the biggest threat to UK stock, as it is the one we've
already experienced here and could well still be circulating
here."
The only way to ensure full protection for stock is to vaccinate
them, he warned. "Once again vaccination in England and Wales will
be voluntary, so the onus is on farmers to protect their own
animals. While some farmers may prefer to see a compulsory
programme in place this could result in slower vaccination of stock
and would mean vets would have to become involved, too."
Farmers ordering vaccine in the next month or so will need to
check the expiry date on vials though, he said. "There are more
than 12m doses of last year's supply left over and these will be
supplied first. But any of last year's vaccine in 20ml vials has an
expiry date of the end of February and some of the 50ml packs
expire at the end of March."
But vet Jules Dare of the Westpoint Vet Group
told the meeting that DEFRA and the vaccine
manufacturers were in discussions about extending the expiry date
of these packs. "So long as the seal hasn't been broken and the
vaccine has been refrigerated, there shouldn't be a problem with
extending the dates."
Looking further ahead, Mr Mulluneux said that at the moment EU
rules only allowed countries to vaccinate against strains of the
disease present in the country. But discussions were ongoing to
allow preventative vaccination against other strains. "This should
allow the UK to protect against BTV1 in due course, depending on
the risk level of the disease spreading here."
Reminding farmers present of the symptoms, Mr Dare said suckler
herd managers should look out for cows with sunburnt udders. "It
appears that bluetongue hypersensitises the udder to sunlight,
meaning the outside of the udder burns easily, while the rest of
the udder remains fine. Cows suffering like this will be reluctant
to allow calves to suckle."
With regard to timing of booster vaccinations for stock
vaccinated last year Mr Dare said farmers should give vaccinations
when it was most convenient to them, bearing in mind it took three
weeks post-vaccination for full immunity to develop. "Booster
vaccinations should be dealt with as soon as is practical. For
cattle this largely means vaccinating them before turnout, to ease
the need to gather them again.
"For sheep farmers there have been questions over whether
vaccine could be given at the same time as other doses, such as
clostridial vaccines. However, vaccine manufacturer
Intervet/Schering Plough has recently said its bluetongue vaccine
can be used at the same time as other killed vaccines in its
portfolio, such as clostridial products."
Vaccine can be given to in-lamb ewes and in-calf cows and
research suggested some maternal antibodies would be passed to
their offspring, he added. "But these antibodies are only likely to
last a couple of weeks."
Mr Dare also said farmers needed to check which vaccine they
would be using, as three were available, all with different
specifications. "Intervet/Schering Plough's product, Bovilis BTV8,
is the one south-east farmers will be familiar with, having used it
last year. This one can be given to all stock older than one month
and sheep require one initial dose and cattle two doses. When it
comes to booster doses, all stock will require one booster
injection.
"Merial's, product BTV Pur 8, can only be given to stock more
than three months old and Fort Dodge's vaccine, Zulvac 8 Bovis, is
only licensed in cattle and can only be given to stock more than
2.5 months old. Prices for the three products will also vary and
all have to be used within eight hours of the seal being
breached."