Page 1043 - Adams and Stashak's Lameness in Horses, 7th Edition

Occupational‐Related Lameness Conditions 1009

Table 9.1. Frequency of diagnostic nerve blocks performed over
a seven‐year period on 17,458 horses in a western performance
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equine sports medicine practice.

performed
Diagnostic block Frequency
Forelimb PD 1,867 (20.0%)
Forelimb abaxial 1,695 (18.2%)
Low four‐point 724 (7.8%)
Tarsometatarsal joint 704 (7.5%)

Forelimb proximal suspensory 648 (6.9%)
Figure 9.53. Draw reins that allow the rider to contact the Hindlimb proximal suspensory 575 (6.2%)
horse’s bit through a single, movable, pulley‐like system are
commonly used as training tools to reinforce the appropriate head Distal intertarsal joint 382 (4.1%)
and neck carriage required of western pleasure horses.
Femoropatellar joint 362 (3.9%)
Fetlock joint (forelimb and hindlimb) 239 (2.6%)
the slow motor control to perform the calculated gaits Femoropatellar, medial femorotibial, and lateral 235 (2.5%)
are a recipe for foot pain. Some believe that the charac­ femorotibial joints
teristically small feet of today’s Quarter horse, which
may not accommodate force dissipation during stance Scapulohumeral joint 103 (1.1%)
phase, exacerbate the effects of concussion. Medial femorotibial joint 100 (1.1%)
Specific farrier approaches are often employed to
enhance the western pleasure horse’s natural, flowing Carpus 91 (0.9%)
forelimb movements. Western pleasure horse’s front feet
are typically shod with aluminum shoes, often with Sacroiliac joint 80 (0.9%)
2°–3° wedges and rim pads to achieve positive palmar
angles and weightless solar support. Medial to lateral Tarsocrural joint 82 (0.9%)
balance is as important in the western pleasure horse as Lateral femorotibial joint 57 (0.6%)
it is in any other discipline, with often special attention
paid to aligning the hoof pastern axis and decreasing the Bicipital bursa 41 (0.4%)
toe distance, also known as “easing the break‐over.”
This combination of shoeing enhances the “quiet” car­ Distal interphalangeal joint 26 (0.3%)
pal action of the western pleasure horse characterized Elbow joint 24 (0.3%)
by minimal carpal flexion. The hindfeet are also typi­
cally shod with aluminum shoes. Carpal canal 18 (0.2%)
The forelimb lameness of a western pleasure horse
with foot pain can present with varying degrees of sever­ Hindlimb digital tendon sheath 15 (0.2%)
ity and is usually exacerbated with the limb on the inside
of the circle. The typical differential list for a western Forelimb digital tendon sheath 13 (0.1%)
pleasure horse with pain localized to a palmar digital TMT and DIT joint 8 (<0.01%)
(PD) nerve block is no different than that for horses of
other disciplines, and the major rule‐outs include coffin Total diagnostic blocks 9,329
joint, navicular apparatus, or sole pain as a result of
concussive forces/shoeing abnormalities. Source: Josh Donnell, Unpublished data.
In a 7‐year demographic review of 17,458 horses that
presented to a practice focusing on competing western
performance horses, diagnostic analgesia was performed
9,329 times. The forelimb PD and abaxial sesamoid Observed pathologic changes include articular cartilage
were the two most frequently performed nerve blocks damage of the coffin joint, deep digital flexor tendi­
(Table 9.1). Over the 7‐year period, 24,910 joints were nopathy, collateral ligament desmopathy, alterations
medicated, with intraarticular coffin joint therapy com­ of the navicular bone itself (sclerosis or bone marrow
prising 4,480 of those cases (Table 9.2). The navicular edema), and navicular bursitis. The array of abnormalities
bursa and pastern joint were medicated in 355 and 113 that have been realized with the use of high‐field MRI
cases, respectively (Table 9.2). continue to advance what is known about navicular
It is the author’s experience that MRI abnormali­ disease in all equine athletes, a paradigm that will
ties that occur within the front feet in this population continue to evolve with continued research and clinical
of horses are similar to those of other disciplines. application.