Page 130 - Adams and Stashak's Lameness in Horses, 7th Edition

96 Chapter 2

PASTERN
The dorsal, medial, and lateral surfaces of the proxi­
VetBooks.ir mal interphalangeal (PIP) joint should be palpated for
enlargement and heat, which may be suggestive of high
ringbone (Figure 2.54). Comparison to the opposite pas­
tern is always recommended. However, it is not uncom­
mon to have the lateral to medial dimensions of one
pastern to be slightly larger than its opposite member.
With the limb off the ground, the distal sesamoidean
ligaments and flexor tendons (superficial and deep digi­
tal flexors) are palpated deeply for pain, heat, and swell­
ing (Figure 2.55). Particular attention is paid to the
lateral and medial branches of the superficial digital
flexor tendon (SDFT) as they attach to the middle pha­
lanx. Tendonitis of the DDFT and/or tenosynovitis of
digital flexor tendon sheath (DFTS) are often identified
by swelling, effusion, and sometimes pain in this region.
Pain on deep palpation of the DDFT just above the heel
bulbs using your thumb may be suggestive of injuries to
the tendon further distally in the hoof capsule. Deep pal­
pation of the lateral and medial eminences (wings) of
the middle phalanx may elicit pain if a fracture is pre­
sent. With the hands placed on the hoof wall, the phalan­
geal joints should be rotated medially and laterally. The
collateral ligaments can be stressed, laterally and medi­
ally, by placing one hand lateral or medial over the pas­
tern joint, while the other hand is used to pull the foot
toward that side (Figure 2.56). This bending force cre­
ates increased tension on the collateral ligaments of the
phalangeal joints.
Figure 2.52. Lower finger marks the site of swelling
and pain associated with fracture of the extensor process.
Upper fingers are applied over the dorsal aspect of the
fetlock to identify synovial distension and thickening of the joint
capsule.

Figure 2.53. Palpation of the heel bulbs to identify heat,
pain, and swelling that may be associated with subsolar Figure 2.54. Palpation of the pastern. Thickening in this region
abscesses. may suggest the presence of ringbone.