Page 324 - Canine Lameness

296 18 Tarsal Region

(A) (C) (E) (G)

TARSAL REGION (B) (D) (F) (H)

Figure 18.8 Examples of dogs with pathology of the Achilles tendon: (A) typical stance with Type IIc Achilles
tendinopathy caused by an intact SDF with a partially disrupted gastrocnemius muscle resulting in the typical
“crab-claw” stance with the (black arrow) digits flexed and the tarsus slightly hyperflexed; (B) typical (black
arrow) swelling associated with Type IIc Achilles tendinopathy; (C) early stages of Achilles tendinopathy as
illustrated by the (white arrow) soft tissue swelling of the tendon; (D–F) chronic Achilles tendinopathy is
frequently associated with (white arrows) calcification and (blue arrow) enthesopathy at the insertion at the
tuber calcanei; (G, H) typical stance and intra-operative appearance with acute, traumatic Type I Achilles injury.

18.5.2 Chronic Gastrocnemius Tendinopathy
Type IIc common calcanean tendinopathy (CCT2c) is a degenerative condition of the GT with an
intact SDFT (Meutstege 1993; Gamble et al. 2017). It is well recognized in medium- and large-
breed dogs and especially in middle-aged Doberman Pinschers and Labrador Retrievers (Corr et al.
2010; Gamble et al. 2017). The degeneration leads to elongation of the GT, thereby causing the
increased flexion of the tarsus. Since the SDF is not affected and the GT is only elongated, animals
are not presented with a completely plantigrade stance but rather with the typical “crab-claw”
appearance from increased tension on the SDF that results in flexion of the digits (Figure 18.7,
Video 18.1). This condition has also been described as an avulsion injury of the GT; however, this
is somewhat confusing since the soft tissue opacities visible on radiographs proximal to the calca-
neus likely represent dystrophic calcification rather than avulsion fragments. A chronic tendinitis
(Type III) has also been described in the literature. This condition may be a precursor to Type IIc
injuries, but little information about this is available.
The etiology of this condition is unclear, but a degenerative process is suspected given the atrau-
matic, chronic, and frequently bilateral presentation (Meutstege 1993; Gamble et al. 2017). As with