Azoturia,
Tying Up or Monday Morning Disease in Horses
Azoturia can happen to a horse
in all kinds of activities Definition: In basic terms a horse or pony
with Azoturia has severe muscle cramps.
Traditionally Azoturia was known as "Monday Morning
Disease" as it would occur in working horses
following a day's rest on Sunday.
Azoturia is also known as "tying up"
- especially in racing circles.
The cramping usually occurs in the muscles of the horse's
hindquarters and the back - causing stiffness and pain.
The pain may be severe enough to cause sweating
and laboured breathing.
The stiffness may be so severe that it prevents
the horse from moving at all.
In exceptional circumstances the horse may go down and be unable
to get up.
The onset of these signs of azoturia are always
associated, in some way, with exercise.
Classically an episode of azoturia will happen while a horse
or pony is being ridden - the
horse will become increasingly reluctant to go forward and the
rider will become aware of increasing stiffness in the hind
legs.
The hind leg stride will become shorter and
shorter. By this stage most horse riders will have dismounted.
Careful examination of the horse will reveal that the muscles
in the quarters and hind legs are hard, and usually painful,
when pressed.
Some horses may show signs of pain which may be confused with
colic - pawing the ground, sweating, turning
round to look at the flanks and perhaps going down on to the ground.
At this point a rider may be tempted to walk the horse
in hand in order to relieve the apparent colic - this
is a grave mistake.
In a case of azoturia any further exercise will
make the condition worse and increase the chance of muscle
damage.
Veterinary attention should be sought immediately!
Keep your horse warm until veterinary help arrives.
If the horse is close to a stable
it can be be very slowly moved to the box, rugged up, and left
until the vet arrives.
If the azoturia has occurred out on a hack,
miles from anywhere, try to keep the horse in the same place and
arrange to bring transport to the horse for the
journey home. Better still call the vet to the horse where it
is - but still arrange for transport back to the stable
yard.
Azoturia is most likely to occur soon after
exercise begins - but is not the only way the problem will occur.
Another variety of this equine muscle cramping occurs at the
end of very strenuous exercise such as racing.
A third variety of azoturia appears in horses that perform relatively
low exertion exercise over a long period - such as long distance
competitions or endurance rides.
What causes Azoturia in a Horse or Pony?
The cramping and pain are a
result of changes in the chemistry of the fluids within the muscle
tissues. As a result of these changes abnormal contractions of
the muscle fibres occur and degeneration of of the tissues takes
place.
The underlying causes of this upset in the muscle chemistry may
be obscure. The classical form of azoturia is
often associated with resting the horse on full
feed rations - hence the name "Monday Morning
Disease" as it used to most often occur after a
days rest on a Sunday.
It seems that that at rest some overfed horses
build up too great a store of carbohydrate in their muscles. When
the horse begins work this carbohydrate is mobilised and causes
changes in the acid base balance of the tissues.
Even with perfect stable management some horse
still succumb to azoturia - in these cases there may be other
imbalances.
The problem is more common in mares and fillies
than in stallions or geldings
- there may be a hormonal influence
Other cases occur in horses with a thyroid imbalance, while others
seems to be associated with an upset in the ration of calcium
to phosphorus in the system.
Other factors may also be implicated as some cases seem to respond
to increased levels of selenium and vitamin E - even though there
may be no actual evidence of deficiency when blood levels are
assessed.
Treatment and care of a horse with Azoturia
The treatment of a horse that has suffered an attack of azoturia
will include rest. painkillers and anti-inflammatory drugs.
Affected horses will benefit from hot towelling of the affected
muscles, heat lamps, or thermal blankets.
The horse will usually require a period of rest according to
the degree of muscle damage. In addition supplements of minerals
and vitamins may be added to the feed to avoid a recurrence.
The feeding and management of susceptible horses is crucial.
Each case will need expert advice from a veterinary
surgeon based upon the results of biochemical analyses. |
