The recent cases of brucellosis in Eastern Scotland and Northern
England have highlighted this disease, which mainland UK had been
free of for almost ten years. However, the disease is still
regularly seen in Ireland and other European countries. Thus
imported cattle pose a major risk to Great Britain's brucellosis
What is Brucellosis?
Brucellosis is infection with the bacteria Brucella
abortus. The most important outcome of infection is abortion,
but infection of the testicles (orchitis) is also seen in
bulls. Brucella is highly contagious, spreading very
easily between cattle as the calf, the membranes and the uterine
fluids all contain large quantities of bacteria. Infected cattle
will often abort only once due to brucellosis and have apparently
normal calvings in subsequent years, but will continue to excrete
large amounts of bacteria after calving.
Brucella can infect humans, causing a chronic disease
known as undulant fever, which is often very resistant to
treatment. Infected cattle will also have bacteria in their milk,
so pasteurisation is essential to prevent human infection.
- Abortion or premature calving
- The fetal membranes are virtually always retained.
- The membranes also often show signs of infection
- In bulls - Swollen testicle (one or both may be involved)
- Joint infection has been reported in other countries)
- Brucellosis cannot be diagnosed on signs alone
- Diagnosis is by laboratory testing of blood or milk samples and
by laboratory culture ofBrucella from the fetal membranes,
vaginal discharge or the milk of infected cows.
- Routine blood and milk testing is used as part of the UK's
strategy to prevent brucellosis
- No treatment is allowed. All infected
cattle and contacts that have been exposed to infection must be
Brucellosis is a notifiable disease, which means that its
control is regulated by law, and all cases where brucellosis might
be suspected must be reported to the local divisional animal health
office. Because the signs associated with brucellosis are not
specific this means that ALL abortions (or premature calvings) of
cattle MUST be reported. The legal definition of an abortion or
premature calving is 'an abortion or calving which takes place less
than 271 days after service, or 265 days after implantation or
transfer of an embryo, whether the calf is born dead or alive'
Once an abortion is reported the animal health office will then
decide whether a visit to take samples is needed, based on the type
of farm and cow factors (such as whether she is home-bred). If an
investigation is required, it is usually carried out by the
farmer's private veterinary surgeon who will come and take the
required samples. There is no cost to the farmer for this unless
tests for diseases other than brucellosis are required. Due to
Great Britain's brucellosis status the number of such tests has
fallen by 75% since 1995 (despite the NADIS data showing no fall in
the number of abortion cases seen by NADIS vets). With the recent
cases, it is likely that the number of investigations will go up,
and it is essential for the prevention of this disease that all
cases of abortion are reported to the animal health office.
It is particularly important to be vigilant with imported
cattle. They may have been tested negative before they were
imported but in many cattle the test will be negative until the cow
calves or aborts. (Indeed this was the case in the recent Scottish
outbreak). It is vital that all imported cattle are tested after
calving even if that calving is normal.
Current regulations require all cattle that have had contact
with infected animals to be slaughtered. This means that if
imported cattle, which are subsequently found to have brucellosis,
are mixed with the main herd before they calve, the cattle they
have been mixed with will have to be slaughtered as well. It is
therefore essential to ensure that imported animals are properly
quarantined until they have tested negative for brucellosis after
calving in the herd for the first time. Work out a proper
biosecurity with your vet before you bring the cattle on-farm.
Brucellosis has been effectively controlled by a statutory
testing programme to identify infected cattle. This has changed
brucellosis from a very common cause of abortion to a very rare
disease. However, as the recent cases show the farming industry
needs to be vigilant to prevent it from becoming a major problem