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F LOCK HEALTH
Sheep infected with footrot and CODD
Scab is caused by a mite living on the
skin of the sheep.
It is incredibly contagious and causes
intense itching leading to production losses.
One of the problems with any sheep is that
they can be carrying scab without showing
signs; in the early stages it is undetectable.
There is also the possibility of mites being
picked up from the transport lorry or mixing
with other wintered sheep.
The only way of knowing for sure that
your sheep do not have scab, is to treat
them on arrival home with an appropriate
macrocyclic lactone injection or to dip
them. 1% moxidectin injection is
recommended by SCOPS, but this must
not be used in sheep that have ever had
or are likely to have the Footvax
TM
vaccination against footrot. There are other
macrocyclic lactone injections available, but
they differ in how long they last and how
many injections are required. Consult your
vet as to which is the most appropriate
treatment for you.
Lice
Although not necessarily a big issue, lice
infestation is often not noticed until there is
a reasonable length of fleece i.e. the winter
months. The signs are similar to scab,
rubbing on fences, nibbling and wool loss,
although the skin is not usually as severely
affected as with scab. Early diagnosis and
treatment with a pyrethroid pour-on is usually
effective in controlling this.
Lameness
Footrot is highly contagious and painful. It
can cause dramatic weight loss and lead to
expensive visits to the wintering to treat
affected sheep. Vaccination before leaving
can help reduce the incidence when the
lambs are away.
All too frequently contagious ovine digital
dermatitis (CODD) and highly virulent strains
of footrot can be introduced into a flock on
the feet of bought in sheep, or sheep that
have mixed with strangers while away. It is
important to not only isolate sheep for at
least three weeks on return so that lameness
can be identified, but inspect feet and either
footbath or spray with antibiotic. Some
lesions can be very subtle and some sheep
may carry bacteria without showing many
signs of lameness.
Quarantine treatment, and vaccination are
two of the elements of the ‘5 Point Plan’ for
lameness control and are a must do for
reducing levels of lameness in your flock.
Clostridial disease
Depending on when the primary course was
given, protection may have elapsed whilst
away. This may mean that a booster may
need to be given when the sheep are away.
Failing that, all sheep should be vaccinated
on return from the wintering as this will put
them onto the same booster interval as the
adult ewes in the next year, i.e. pre-lambing.
This important treatment is often forgotten,
leading to a break in protection and potentially
the cause of apparent lack of protection in the
adult flock. Similarly if lambs were only
vaccinated with a 4in1 vaccine, there are
some diseases more likely in late winter,
which may cause unexpected losses in
sheep where there wasn’t adequate cover.
Scab
Johne’s
Often overlooked as a problem in sheep,
Johne’s is caused by a bacteria that grows
in the gut and causes thickening of the
bowel leading to weight loss and wasting.
It is spread on pasture. Spreading slurry on
grazing fields is a known way of infecting
pasture with the bacteria. There is a small
risk that grazing sheep on farms with a
known history of Johne’s in the cows does
two things; sheep can act as a way of
dispersing the organism around the farm into
previously grazed or mown fields, also there
is a small risk that the sheep may themselves
become infected with the organism.
Johne’s in cattle and sheep has been shown
to be increased when youngstock are
exposed to the organism. It may be worth
having a discussion with your own vet and
the person who owns the farm about what
Johne’s might mean to your sheep.
AUTUMN 2015 ISSUE
LIVESTOCK MATTERS
8
Sheep scab
For more information on the
XLVets Make Your Farm Your
Fortress and Stand up to Sheep
Lameness initiatives contact your
XLVets practice.