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Do not be fooled by the exotic names - just
because they are called African Horse
Sickness or West Nile Fever it does not mean
these diseases will stay in that part of the
world and abide by some line on a map.
We only have to look at the experience in the
farming sector, with the arrival of Blue Tongue
Virus (BTV) in 2007 and Schmallenberg Virus
(SBV) last year to know that disease patterns
are changing.
Two factors have fuelled this change:
●
Increased movement of animals around
the world, for competition or breeding
purposes.
●
Climate conditions favouring the insect
vectors responsible for spreading some
of these diseases.
What many of these emerging diseases
have in common is that infected biting insects
spread them. Whilst we can contain and
control the animals the same cannot be said
for these insect vectors. Infected midges may
be blown large distances or may hitch a lift
among inanimate objects on aircraft.
Potential Disease Threats
African Horse Sickness (AHS)
●
Viral infection spread by midges
/mosquitoes.
●
As the name suggests, widespread in
Africa but also has occurred in southern
Europe. Not yet in the UK.
●
Causes respiratory distress, heart failure
and death.
West Nile Fever (WNF)
●
Viral infection of wild birds spread by
mosquitoes/ticks.
●
Incidental infection of horses and humans.
●
Causes fever and nervous signs in horses.
●
Exposure to the virus has been identified
in wild birds in the UK but no active
virus or clinical signs as yet. Risk from
migrating birds.
Equine Infectious Anaemia
(EIA) or Swamp Fever
●
Viral infection spread by biting horse flies
and stable flies.
●
Causes intermittent fever, anaemia,
and emaciation.
●
Cases have been identified in UK in
2010 and 2012.
Equine Viral Arteritis (EVA)
●
Viral infection contracted during mating,
AI with infected semen, and through
respiratory secretions.
●
Causes fever, swelling of genitals/legs
and abortion.
●
Active worldwide. Cases in the UK in
2010 and 2012.
●
Stallions can become asymptomatic
carriers or shedders.
Equine Piroplasmosis (EP)
●
Protozoa spread by infected ticks.
●
Causes jaundice and anaemia. Some
horses can become lifelong carriers.
●
Widespread in Mediterranean countries.
●
Disease not present in the UK. Cases
have been diagnosed in Ireland.
●
Ticks capable of being vectors have
been identified in UK.
Dourine
●
Protozoa spread during mating or by
infected semen at AI.
●
Causes swelling of genitalia and
neurological signs leading to paralysis.
●
Present in Eastern Europe. Diagnosed in
Italy in 2011.
The major consequences of exotic diseases
entering the UK are compromised health and
welfare of horses as well as disruption to all
equine activities. Control of emerging disease
is through import controls, which require
laboratory testing and surveillance of
imported animals and semen. Legislation is
also in place to help protect the UK horse
population. Apart from Equine Piroplasmosis,
all the diseases mentioned above are
notifiable; any suspicious symptoms must be
reported to the Animal Health authorities who
will instigate isolation, movement restrictions
and testing until the all clear is given. There
are also codes of practice that horse owners
should follow to play their part in preventing
disease coming into this country.
Emerging disease
threats
Veterinary Surgeon
Andy Cant
XLVets Equine Practice
Northvet Veterinary
Group
Andy Cant BVMS CertVR MRCVS
, Northvet Veterinary Group
EMERGING D I SEASE
19
EQUINE MATTERS