Page 78 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Musculoskeletal system: 1.2 The foal and developing animal 53

VetBooks.ir 1.95 1.96

Fig. 1.96 More severe case of bilateral acquired
distal interphalangeal joint flexural deformity, with a
Stage II deformity in the right forelimb.

Fig. 1.95 A yearling pony with an acquired flexural
deformity of the left forelimb distal interphalangeal
joint. Note the upright, boxy and contracted left
forelimb foot, with the heel raised just off the ground.
Stage I deformity.

DIP joint deformity include a prominent bulge at in advanced cases and ‘knuckling over’ and stum-
the coronary band, ‘dishing’ of the dorsal hoof wall, bling are sometimes seen at the walk in these cases.
an increase in heel length and eventually a ‘boxy’ Palpation of the AL-DDFT may reveal some DIP
foot (‘club foot’) appearance (Stage I DIP joint joint component. Acquired carpal flexural deformi-
deformity) (Fig. 1.95). In severe cases the heel does ties are sometimes seen in adults in a chronic, non-
not contact the ground and the dorsal hoof wall weight-bearing limb.
goes beyond the vertical (Stage II DIP joint defor-
mity), with weight borne at the toe (Fig. 1.96). Differential diagnoses
Excessive wear at the toe of the hoof may allow None.
infections to establish and further decrease weight
bearing on the limb. Careful palpation of the acces- Diagnosis
sory ligament of the deep digital flexor tendon The clinical history and findings are diagnostic.
(AL-DDFT) (inferior check ligament), both weight Radiography of the foot of the affected limb may
and non-weight bearing, may reveal increased reveal bone remodelling at the tip of the pedal
tension. MCP deformity is less common, mainly bone in severe cases of DIP joint deformity, which
affects the forelimb and presents after a period may affect the long-term prognosis in some cases.
of compensatory growth as an upright conforma- Infrequently, persistent infection in the hoof at the
tion with intermittent dorsal knuckling in early toe can be associated with damage and infection in
or mild cases (Fig. 1.97). The latter is persistent the pedal bone.