Page 30 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Musculoskeletal system: 1.1 A pproach to the lame horse 5

VetBooks.ir 1.9 1.10

Fig. 1.9 The front feet of a horse undergoing Fig. 1.10 This horse suffered a severe trauma to the
corrective trimming and shoeing. Note the right foot coronary band and hoof of this foot several years ago.
has a long toe with a broken-back foot pastern axis. It is now left with a permanent injury to the coronary
The left foot has had the toe trimmed back to band, which is leading to a crack in the quarter of the
re-establish a straight foot pastern axis. hoof.

contralateral foot may indicate chronic lameness in
1.11
that limb. Any hoof horn defects (e.g. hoof cracks)
should be noted (Fig. 1.10).
The posture or stance may indicate the horse’s
response to acute or chronic pain in one or more
limbs (Fig. 1.11) (e.g. a non-weight-bearing lame-
ness due to a simple foot abscess or a long-bone
fracture, or subtle unloading of the limb in chronic
intertarsal joint pain of the hindlimb). More spe-
cifically, a dropped elbow posture is indicative of a
loss of function of the triceps apparatus, most com-
monly due to radial paralysis or olecranon fractures
(Fig. 1.12).
Palpation of the affected limb(s) adds informa-
tion to the visual appraisal. Knowledge of the nor-
mal musculoskeletal anatomy is a prerequisite,
although comparison with the contralateral limb
may be useful, unless the condition is bilateral (e.g.
osteochondrosis dissecans of both tarsocrural joints
Fig. 1.11 Observation of the forelimb stance of a might exhibit bilateral tarsocrural joint distension).
horse from the right side. Note the acquired carpal If time permits, all the limbs, both weight bear-
contracture of the right forelimb in this case of a ing and held off the ground, the neck and the back
chronic proximal suspensory ligament insertional should be palpated sequentially regardless of the
desmitis of over 2-years’ duration. suspected lame limb suggested by the owner, unless