Page 1062 - Adams and Stashak's Lameness in Horses, 7th Edition

1028 Chapter 9

poor hoof care, thin soles, broken hoof walls, and exer­
cise on hard surfaces. Horses with distal phalanx osteitis
VetBooks.ir lameness that is worse when worked on hard surfaces
typically present with a history of bilateral forelimb
(e.g. gravel, pavement, dry ground). Most horses with
distal phalanx osteitis have increased sensitivity to hoof
testers across the toes, quarters, and sometimes the heels.
When trotted in hand, affected horses have clinical signs
of bilateral forelimb lameness, which may be worse
when trotted in a circle. Approximately 50% of horses
improve following a palmar digital nerve block, and the
remaining 50% improve following a midpastern ring
block or an abaxial sesamoid nerve block. The author
prefers a midpastern ring block because it is more spe­
cific for the foot and pastern.
Radiographic findings associated with nonseptic
osteitis include lucency along the margins of the distal Figure 9.64. Cross section of a Clydesdale’s foot demonstrating
phalanx and proliferative new bone formation along the the long toe and concavity of the dorsal hoof wall that may
margin of the distal phalanx, which can extend up the predispose these horses to laminitis.
hoof wall. Treatment includes NSAIDs and corrective
farriery, which should include the placement of a wide‐
web shoe with a rolled toe. The inside of the shoe should
be filled with shock‐absorbing material such as dental
impression material. This type of material is very impor­
tant in managing the lameness because it protects and
supports the sole to minimize compression and concus­
sion to the distal phalanx. Cases that do not respond to
corrective farriery and sole support may be considered
for a palmar digital neurectomy.

Hoof Cracks
Hoof cracks involving the insensitive and sensitive
laminae are common in draft horses. This is in part due
to the difficulty in keeping the feet trimmed but may also
be secondary to previous coronary band trauma. More
than 75% of hoof wall cracks in draft horses involve the
insensitive laminae, and these cracks can be managed Figure 9.65. Cross section of a Clydesdale’s foot with severe
with corrective shoeing and proper trimming of the hoof chronic laminitis. Significant movement of the distal phalanx is often
wall. Grooving the hoof wall at the most proximal aspect present at the initial evaluation of draft horses, and preventing
of the crack can be useful in preventing crack propaga­ further movement can be challenging.
tion toward the coronary band. If desired, insensitive
hoof wall cracks can be managed with hoof wall staples are also commonly shod with long toes and exercised on
and epoxy/acrylic repair, with a good prognosis. hard ground, which also may predispose them to lamini­
Cracks involving the sensitive laminae result in lame­ tis (Figure 9.64). Laminitis can involve rotation, distal
ness and require stabilization. Acceptable methods of displacement of the distal phalanx (sinking), or a com­
stabilization include staples, acrylic repair, and a bar bination of rotation and distal displacement of the third
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shoe with clips on each side of the crack. 18,19 If epoxy/ phalanx. The author has found no universally success­
acrylic repair is chosen, it is very important that the crack ful method for managing laminitis in draft horses.
be completely cornified prior to repair to reduce the risk Laminitis is difficult to stabilize so that no further rotation
of abscessation. Hoof wall cracks associated with coro­ or distal displacement occurs (Figure 9.65). The risk fac­
nary band defects may require surgical reconstruction of tor that most likely explains this is the large body weight.
the coronary band defect to prevent continued cracks. The cornerstone of management is corrective shoe­
The prognosis is usually good. The most common com­ ing, and working with a farrier is crucial to a successful
plication is infection associated with hoof crack repair. outcome. The author prefers the application of wedge
shoes with sole/frog support to relieve the pull of the
deep digital flexor tendon and to support the sole and
Laminitis frog. Because of draft horses’ large foot size, custom‐made
Laminitis, although not diagnostically challenging, is shoes are often required. Some draft horses respond well
difficult to manage in draft horses because of their heavy to application of heart‐bar shoes with added sole and
body weight. Common causes of laminitis in draft horses frog support. Draft horses with distal phalanx rotation
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include grain overload, following gastrointestinal disease greater than 15° are candidates for deep digital flexor tenotomy.
(e.g. diarrhea, postabdominal surgery), retained placenta, This should not be considered as a salvage procedure
and contralateral weight‐bearing lameness. These horses but as a useful tool in the management of laminitis. It