Page 329 - Canine Lameness

18.7 ­ctrF gesrresres ooracgoe ctrf rFesral reg o 301

(A) (B) (D) (F)

(C) (E) (G) TARSAL REGION

Figure 18.11 Other diseases affecting the tarsal region: (A–C) pes varus deformity in a miniature
Dachshund; note the marked varus of the distal limb, (white arrow) shortening of the medial cortex of the
tibial diaphysis compared to the lateral cortex, and widening of the medial aspect of the tibiotarsal joint.
(D, E) Erosive immune-mediated polyarthritis in an adult dog that resulted in bilateral tarsal hyperflexion
and carpal hyperextension; note that the (white arrow) lytic changes are limited to the distal tarsal joints
resulting in instability at the tarsometatarsal joint. (F, G) Patient with chronic OCD and chronic
enthesopathy of the medial collateral ligament; (F) the dorsoplantar view shows (white arrow) flattening of
the medial trochlear ridge consistent with OCD; and (G) image of the patient illustrating (white arrow)
severe periarticular swelling.

joint effusion. Dogs with advanced erosive arthritis may experience joint luxations (Figure 18.11)
and walk plantigrade or have other joint deformities. Please refer to Chapters 9 and 13 for further
details regarding joint fluid analysis and the classification of IMPA, respectively.
Septic arthritis should also be considered as a differential diagnosis, but in the tarsus it is much
less frequent than immune-mediated disease.

18.7.1 Tarsal Deformities
Pes varus is a deformity of the distal tibia caused by premature closure of the medial distal tibial
physis (Radasch et al. 2008). The asymmetric closure results in varus angulation of the distal tibia.
It may be unilateral or bilateral. Since the majority of affected dogs are Dachshunds, the disease is
thought to have a genetic component, but it may be caused by trauma in other dogs. Affected dogs
have a “bow-legged” appearance (Figure 18.11) and variable clinical signs. The deformity may be