Since restocking Cumbria after foot and mouth there have been
over 90 herds, which have had tuberculosis. This has resulted in
over 295 cows being slaughtered. Not all of these cases have occurred
in restocked herds, but the majority are associated with cattle
that have been brought into the county, writes Graham Brooks, of
Coomara Veterinary Practice, Carleton, Carlisle.
There are two
means by which Tuberculosis can be spread. Within a herd or between
herds then close contact between an infected animal and a non-infected
animal is required. The bacteria are normally excreted in nasal
and mouth secretions, milk and occasionally urine and faecaes.
Because it is not possible to tell just by viewing if a cow is
infected cow or not, it is necessary to keep your cattle separate
from other possibly infected cattle.
The other means of spread
is by environmental contamination from infected wildlife species.
Because Cumbria was free of tuberculosis before Foot and Mouth,
hopefully we can assume that our native wildlife is not infected
with the disease. However, if it does become infected then from
the examples set by other parts of the country it is unlikely that
the county will be free of the disease for a considerable time.
At present in this country Tuberculosis is diagnosed by using
the comparative intra dermal tuberculin test. However, this test
by no means 100 per cent efficient at detecting all infected animals.
An outbreak of Tuberculosis on your farm can have serious implications.
These include movement restrictions preventing you from selling
except under licence direct to slaughter and from buying in replacement
The length of time the movement restrictions stay in place
depends on the severity of the disease but they will until all
bovine animals on the premises have had a second intra dermal test
a minimum of 42 days after the initial test. All animals have to
pass this test for the restrictions to be lifted. Some animals
are classified as inconclusive. These animals have to be placed
in isolation and are retested after 42 days.
What can you do to
prevent your herd being infected? As already stated the two main
sources of infection for your cattle are other infected cattle
and wildlife. Therefore to prevent infection entering your herd
you need to maintain suitable biosecurity measures. These would
include ensuring all your fences are such that your stock cannot
make contact with your neighbours. A three-meter gap is a minimum
between two fields. Ensure that all food stores are secure against
wildlife to prevent contamination.
A lot of wildlife are attracted
to molasses feed blocks etc. therefore these should be raised off
the ground by at least 30 inches. The same applies to all water
and feed troughs. If you are buying in cattle then it is wise to
inquire when the herd was last tested for Tuberculosis and at what
frequency the tests have been carried out. If the herd has not
been tested in the last three months consider having a private
intra-dermal test carried out before buying.
Because of the inefficiencies
in the test, all cattle entering the farm should be isolated and
re-tested after 42 days. Tuberculosis bacteria can survive in damp
places in the environment for several months. Therefore all farm
buildings that have been used for isolation should be cleaned and
disinfected before reuse. Ensure that you have your routine tuberculosis
test carried out as soon as possible after it becomes due. If your
herd is infected the sooner it is found the less animals that will
Please try to have your herd tuberculin tests carried
out as soon after the due date as possible. The use of an isolation
period for cattle entering the farm is an ideal time to test cattle
for other diseases such as BVD and IBR and to carry out any necessary
vaccination programmes to prevent newly introduced stock becoming
infected with diseases that are endemic in your herd.
health plans should have a section in them dealing with the procedures
for introducing new livestock to the farm. This is best arranged
with your own Veterinary Surgeon who should know the disease status
of your herd and can instigate the correct vaccination and testing
regime for you.