DISEASE
A danger
which lurks
in your soil...
...and it can kill both you
and your livestock
S
mallholders are a tough
bunch. Most of us
wouldn't let the odd cut
or scratch bother us. But by
the nature of our lifestyle,
we're exposed to injuries or
even bites from our animals
and so we are encouraged to
keep a record of when last
we had a tetanus injection.
Moreover, our animals are
just as vulnerable to puncture
wounds from standing on
nails or scratches from rusty
wire, as well as inherent
danger when they are
dehorned, castrated, tattooed
or have their tails docked.
Tetanus, or lockjaw, is caused
by a toxin produced by
bacteria which are present in
the soil, as well as the
intestinal flora of humans and
animals, in faeces, on human
skin and on teeth. The
bacterium Clostridium tetani
survives in the environment
for long periods of time. It
enters the body through
wounds, particularly puncture
wounds if the wound is dirty,
and is not affected or
destroyed by disinfectants.
Puncture wounds on the sole
of the foot are common sites
of infection.
Both humans and animals
can contract tetanus.
The incubation period (the
time from injury to the onset
of the first symptom) can be
as short as 24 hours and as
long as many months. The
average time is seven to ten
days. Typically, the further the
injury is from the central
nervous system, the longer
the incubation period.
Tetanus toxin affects the
nerves around the site of
injury or wound and then
travels to the spinal column,
and from there attacks nerves
controlling the muscles of the
body. This causes progres-
sively worsening muscular
stiffness and spasm. The
affected person or animal will
become stiff and have
difficulty moving and eating.
In horses the third eyelid
(membrana nictitans, a
membrane which can be
easily seen at the inner corner
of the eye) starts to protrude
across the eye, particularly if
the horse is startled. The tail
is often held out straight and
the horse develops an
anxious expression because
of facial muscle spasm. Any
stimulus such as loud sound,
bright light or touch can
exacerbate the signs. The
horse may sweat. In
advanced cases the horse will
collapse with spasms and
convulsions and death will
follow from respiratory
failure.
Because some sheep undergo
several maintenance
procedures, such as castra-
tion, ear-marking, tail-
docking, dehorning and
debudding, they are highly at
risk for contracting tetanus.
In sheep symptoms of tetanus
infection include muscle
stiffness and spasms, bloat,
panic, uncoordinated walking
and movements, and the
inability to eat and drink.
Among pigs the most
common source of infection
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