Signs and Symptoms of Fatigue in the Equine
by Dr. B. C. Throgmorton, DVM

    STAGE ONE:

The equine athlete is eager, tense, and anxious to go.
They are willing to try and out run every other horse.
Strive to be in the lead of the pack, don't want others to pass.
Little attention paid to the rider, fair to poor response.
 
   STAGE TWO:
Willing to give up quest to keep up with other horses.
More responsive to rider.
Less enthusiasm to tackle each incline and decent.
Rdie gait smooths out, less oomph in each stride, slower gait.
Less competitive with other horses, more willing to to let them pass.
Pulse and respiration slightly elevated after 10 minutes of rest.
Gut sounds are reduced.
 
   STAGE THREE:  (Rider now takes over)
Rider starts to urge horse to keep up.
Horse will respond, but for shorter and shorter time periods.
Horse will try and turn off trail and stop.
Cranky attitude.  May lay ears back at other horses.
Pulse and respiration will invert and stay elevated after 10 minutes of rest.
Pulse and respiration higher than normal after 30 minutes = fatigue.
Little interest in food, and sometimes water as well.
Head down, ears droop, eyes dull & glazed, senses dull, unresponsive to
       flies and objects around him.
Anal sphincter relaxed, slow response to touch.
Movement slow, shuffling with toes dragging, uncoordinated.
Thumps may occur after a few minutes rest.
 
   STAGE FOUR:  (Horse approaches serious trouble)
Dry cotton mouth, sticky saliva.
Mucous membranes either:
     1:  Cyanotic (blue) from poor circulation
     2:  Injected (red) due to toxemia
     3:  Pale (white) due to shock
Capillary refill very slow, more than 3 seconds.
Severe dehydration, skin pliability along neck slow or absent.
Elevated pulse over 60 beats per minute after 30 minutes rest.
Respiration deep and rapid, nostrils flared.
Gut sounds absent.  (85% of blood flow goes to muscle in exercise)
Unwilling to move or slow to respond.
Extreme depression, no desire to eat or drink.
Anal sphincter open and unresponsive to touch.  (Open 1 to 2 fingers)
May lay down and refuse to get up.
Colic - signs  (uneasy, kicking at belly, looking at sides, lying down and rolling)

Treatment for fatigue sound begin at this time.
 

   Dr Throgmorton is a NATRC veterinary judge who was instrumental in setting up the rules
   for NATRC vet judges to follow.