Page 111 - BSR 2022

“Learning to ‘read’ a horse’s facial expressions and postures at rest or under saddle helps an owner or trainer become more sensitive to problems that arise.”
VETERINARY VIEWS
of these behaviors within a five-minute work period is suggestive of some level of musculoskeletal pain.
• Repeated changes of head position up or down
• Head tilted or tilting repeatedly
• Head in front of vertical (>30°) for ≥ 10 s
• Head behind the vertical (>10°) for ≥ 10 s
• Head position changes regularly, tossed or
twisted from side to side, corrected constantly
• Ears rotated back behind vertical or flat
(both or one only) ≥ 5 s; repeatedly lay flat
• Eye lids closed or half closed for 2–5 seconds
• Sclera (white of the eye) exposed
• Intense stare for 5 seconds
• Mouth opening or shutting repeatedly
with separation of teeth, for ≥ 10 s
• Tongue exposed, protruding or hanging
out, and/or moving in and out
• Bit pulled through the mouth on one side
• Tail clamped tightly to middle or held to
one side
• Tail swishing large movements –
repeatedly up and down; side to side or
circular; during transitions
• A rushed gait (frequency of trot steps >
40/15 s); irregular rhythm in trot or canter;
repeated changes of speed in trot or canter
• Gait too slow (frequency of trot steps
<35/15 s); passage-like trot
• Hind limbs not following tracks of
forelimbs but deviate left or right; on three
tracks in trot or canter
• Canter repeated leg changes: repeated
strike off wrong leg; change of leg in front
and/or behind; disunited
• Spontaneous changes of gait (e.g. breaks
from canter to trot or trot to canter)
• Stumbles or trips repeatedly; repeated toe drag
• Sudden change of direction, against rider
direction; spooking
• Reluctant to move forward (has to be
kicked or verbal encouragement), stops
spontaneously
• Rearing
• Bucking or kicking backwards
Some lame horses score < 8 because they are stoic or experiencing low-grade lameness, while some behave normally
in easy work, but only show signs of pain when performing more biomechanically demanding movements. Some horses may
appear comfortable in trot and score < 8 but are very uncomfortable in canter with scores > 8. The majority of non-lame horses score only 2, with the most common behaviors demonstrated by opening of the mouth and the front of the head held behind the vertical. The most common score for lame horses
is 9 but some may show up to 16 different behaviors. When pain-causing lameness is removed by nerve blocks (anesthetic), there is a substantial reduction in the behavior score thereby corroborating that the behaviors reflect pain or discomfort.
Other important observations reduce or disappear when pain-causing lameness is removed:
• Teeth grinding
• Constantly chomping on the bit
• Sweating disproportionate to work done
and environmental temperature
• Increased respiratory rate disproportionate to
work done and environmental temperature • Increased respiratory noises in work the
horse finds more difficult
• Grunting
• Increased blink rate
• Abnormal behavior when tacked up or mounted
Training of the person assessing all behaviors improves accuracy of its application.
OBEL LAMINITIS SCALE
Horses with laminitis can be scored subjectively as to pain level when walking or trotting in a straight line. The scale used is referred to as the Obel Grading System:
• Grade 1 = weight shifts from one foot to the
other; no lameness at walk; shortened stride
at trot.
• Grade 2 = Moves willingly at walk and
trot but stride is noticeably shortened and lame; willing to lift foot off the ground with no difficulty.
• Grade 3 = Lameness is obvious at walk and trot; reluctant to move; and resists attempts to lift feet.
• Grade 4 = Marked reluctance or refusal to move; difficulty bearing weight at rest, so it is nearly impossible to lift a foot.
Studies suggest that the HGS correlates well with the Obel laminitis scale and therefore pain assessment is obtainable
without having to ask the lame horse to walk or trot.
COMPOSITE MEASURE PAIN SCALE (CMPS)
A Composite Measure Pain Scale (CMPS) combines multiple, simple descriptive scales each of which describes specific behaviors and/or physiological parameters. Composite pain scales are all
a bit different, with singular importance applied to different parameters depending on the horse’s condition. For example, horses undergoing abdominal surgery
are evaluated for eight behaviors and one physical parameter such as leg lifting for lameness. For orthopedic procedures, the scale measures weight-bearing behavior
and other behaviors like tooth grinding, lip curl, pawing, and sweating. This evaluation is in addition to facial expressions and attitude. Behavior-based assessments of pain are appropriate when applied by trained veterinarians in order to assess the location and the intensity of pain.
One proposed composite pain detection method is the Equine Pain Scale (EPS), which looks at specific multiple behavioral parameters: Gross pain behavior, activity level, position in the stall, posture and demeanor, weight bearing, head position, head movement, attention towards the painful area, interactive behavior, and appetite along with the equine pain face.
THE BOTTOM LINE
Learning to “read” a horse’s facial expressions and postures at rest or under saddle helps an owner or trainer become more sensitive to problems that arise. çHorses speak volumes through their body and behavior if one knows what to look for. Early recognition of an issue enables prompt veterinary attention and appropriate therapeutic measures to mitigate a horse’s discomfort and prevent development of secondary problems. Appropriate treatment is also likely to enhance performance and promote the development of a “happy athlete,” while optimizing equine welfare.
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