How to spot contagious equine metritis, what to do if you suspect
it and measures to prevent its spread.
From:
Department for
Environment, Food & Rural Affairs and Animal and Plant Health
Agency
Contents
-
Latest situation
-
How to spot CEM
-
Laboratories and CEM
-
How CEM spreads
-
Preventing and
controlling CEM
-
Legislation relating to
CEM
Contagious equine metritis (CEM) is a venereal disease
that affects horses, donkeys, mules, zebras and other members of
the equid family.
It doesn’t affect humans.
Latest situation
On 9 June 2021 a stallion at an equine premises in Devon tested
positive for Contagious Equine Metritis (CEM).
Three mares which had close contact with the infected horse at
the same premises are currently under investigation. The source
of infection is believed to be contact with a stable mate abroad,
before arriving in the UK.
The last outbreak of CEM in Great Britain was in
April 2020 in Scotland.
How to spot CEM
Stallions do not show clinical signs of the disease, but they can
carry it.
In mares you should look out for discharge from swollen genitals,
especially 1-6 days after mating.
Infected mares may also be temporarily infertile, so if your
animal is failing to get into foal, get it examined by a vet.
Laboratories and CEM
CEM is a reportable disease for laboratories. If a laboratory
suspects the disease is present in a sample from your animal,
they must contact their nearest Animal and Plant
Health Agency office immediately. Failure to do so is an
offence.
How CEM
spreads
CEM spreads from
horse to horse during mating. It can also spread when horses are
artificially inseminated.
Preventing and controlling CEMPreventing
CEM
You can use the Horserace Betting Levy
Board contagious equine metritis code of practice to help
prevent infection and to stop the disease spreading.
You can also prevent CEM by practising strict
biosecurity on your premises.
If you suspect CEM
You should:
- tell your vet immediately - they may take samples from your
horse for lab testing
- isolate any horses you think are affected
- stop the suspect horses mating
- avoid using semen from stallions with suspected or confirmed
infection
If CEM is
confirmed
CEM can be
treated with antibiotics. There are no public health
implications.
Where owners of affected horses agree to comply with the HBLB code of practice,
the affected animal and all contacts will be tested and treated
following advice from industry disease experts and the British
Equine Veterinary Association. The premises will be restricted
from exporting any horses or equine germinal products until the
cases are successfully resolved. These procedures have been in
place since April 2020, following an initial pilot.
Where owners choose not to comply with the code of practice, the
outbreak will be controlled in line with the contingency plan for
exotic notifiable diseases.
Further information on prevention and control
What happens when a
notifiable disease is suspected or confirmed
Legislation relating to CEM
The main domestic legislation on CEM is the Infectious Diseases of
Horses Order 1987.
