Basic HTML Version
VACC INAT ION
Equine
Vaccination
Laura Ruby BVSc MRCVS,
Calweton Equine
Veterinary Surgeon
Laura Ruby
XLEquine Practice
Calweton Equine
l
muscle stiffness/spasm;
l
difficulty moving;
l
elevated tail;
l
sweating.
l
protrusion of the third eyelid across
the eye;
It is a neurotoxin released by the
bacteria that causes the following
classic clinical signs:
Tetanus
Tetanus is caused by the organism Clostridium
tetani; this lives in the soil and enters through
wounds or surgical sites. Horses are
particularly susceptible to tetanus and the
disease can be fatal. The bacteria do not
need oxygen to live and so rapidly multiply
within the damaged tissue.
Tetanus carries a high fatality rate however it
is easily preventable with vaccination.
Equine Influenza Virus
Equine influenza virus is a highly contagious
viral disease affecting the respiratory system. It
has a very short incubation period (1-3 days)
and spreads rapidly amongst naïve populations.
Affected horses will typically present as dull
and depressed with a fever, nasal discharge
and most cases will develop a cough. The virus
is usually self-limiting, although the damaged
respiratory system is susceptible to secondary
bacterial infection requiring veterinary attention.
Equine influenza is more severe in donkeys and
carries a higher fatality rate. Prevention is
achieved with vaccination.
Strict competition guidelines are present
and specific vaccination schedules must be
followed. The vaccine requirements are
available on the British Horseracing
Authority/FEI websites.
Equine Herpesvirus (EHV)
The two most common herpesviruses causing
disease in horses are EHV-1 and EHV-4.
EHV-1 can cause respiratory disease,
abortion in mares and neurological disease.
EHV-4 is associated with respiratory disease
in younger animals.
l
Horses with respiratory disease often present
with fever, nasal discharge and a cough.
l
Infection of the mare during pregnancy
can result in abortion, usually in the last
three months of pregnancy.
l
With the neurological form, ataxia (inability
to control the movements of muscles) can
vary from mild stumbling to collapse.
Vaccination against herpesvirus is only
protective against abortion. It can be given
to horses to minimise respiratory signs,
however it will not completely stop them from
contracting EHV-1 or EHV-4.
Strangles
Strangles is caused by the bacterium
Streptococcus equi subsp. equi. Vaccination
can be used as part of a strangles
management programme; it can form an
important element in preventing strangles
outbreaks on yards, but it is not a substitute
for good stable management and disease
awareness. The vaccine available aims to
reduce clinical signs and the incidence of
lymph node abscesses.
Equine Viral Arteritis (EVA)
EVA is a notifiable disease. Clinical signs
include fever, nasal discharge, conjunctivitis,
swelling of the legs, eyelids, mammary gland
or scrotum and abortion. Some infected
horses will not display any clinical signs.
Breeding stallions must be blood tested at
the beginning of each breeding season to
prove they are not infected with the virus,
and breeding mares must be tested after
1st January and within 28 days of entering
a stud/AI centre. Routine vaccination
against EVA is not performed but in some
circumstances it may be appropriate.
Equine Influenza vaccination record
17
EQUINE MATTERS
Vaccines
are an important preventative measure against diseases
affecting the health and performance of horses. The two diseases
most commonly vaccinated against are tetanus and equine influenza;
however there are also vaccines available against herpes virus,
strangles and equine viral arteritis (EVA).