Page 147 - Adams and Stashak's Lameness in Horses, 7th Edition

Examination for Lameness 113

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Figure 2.97. Typical toe‐out, hock‐in stance that often accompa-
nies problems within the hip and pelvic region.
Figure 2.96. Swelling of the femoral region associated with a
fracture of the distal femur in a yearling Quarter horse.
atrophy, or asymmetry in the epaxial musculature
PELVIS should also be noted.
Palpation is usually best performed with firm finger­
Visual identification of asymmetry of the bones and tip pressure using both hands simultaneously
musculature of the pelvis is an important aspect of exami­ (Figure 2.101). Alternatively, the palm of the hand can
nation of the pelvis. This includes the tuber coxae, the be used to apply downward pressure to the epaxial mus­
tuber ischium, the tuber sacrale, and the gluteal muscles cles (Video 2.3). Palpation of the epaxial muscles lat­
2
on each side. Asymmetry of the bony pelvis often suggests eral to the dorsal spinous processes along the entire
a pelvic fracture, subluxation of the sacroiliac region, or length of the back should be performed. Many horses
fracture of the specific bony prominence. Gluteal muscle may respond to downward pressure in the lumbar
atrophy often accompanies chronic pelvic fractures but region by ventroflexing their backs, but this response
can be seen with any chronic hindlimb lameness often fatigues and withdrawal is less prominent. In
(Figure 2.98). Crepitus associated with pelvic fractures horses that have clinically significant back pain, ventro­
can usually be elicited by swaying the horse from side to flexion of the back is often severe, and any increase in
side or can sometimes be detected on rectal examination. finger‐ or palm‐applied pressure greatly increases this
response. The horse attempts to “drop down” to get
away from hand pressure. Palpation may also cause the
BACK horse to vocalize, swish its tail, or actually kick out
behind. Back palpation is somewhat subjective, and,
Visual assessment of the horse’s back includes therefore, the assessment requires clinical experience. In
observing the muscle contour from the side and axial some cases, tightening of the longissimus dorsi muscle
alignment from the rear (Figure 2.99). The dorsal may be felt with palpation rather than a painful with­
spinous processes should be palpated for axial align­ drawal response. This usually signifies that the horse is
ment, protrusion or depression, swelling, and inters­ attempting to fix the vertebral column because ventro­
pinous distance (Figure 2.100). Any muscle swelling, flexion is painful. 15