Page 186 - Canine Lameness

158 12 Distal Limb Region

DISTAL LIMB REGION

(A) (D)

(B) (E)

(C) (F)

Figure 12.8 Clinical appearance with disruption of the superficial and deep digital flexor tendons (SDF/
DDF) in two patients. Patient I (A–C): (A) normal leg for comparison; (B, C) disruption of the SDF only of the
fourth digit; note the loss of the flexed angle of the proximal interphalangeal joint and that the digit
appears to lie parallel to the contact surface (i.e. the claw is elevated and approximately parallel to the
ground). Patient II (D–F): (D) normal leg for comparison; (E, F) disruption of the SDF and DDF of the third
and fourth digit; note that compared to Patient I (B, C) the claw is elevated beyond parallel due to the
complete loss of the flexor mechanism.

opposite number; however, resistance from the deep digital flexor is still palpable (i.e. inability
to elevate the toe dorsally completely). The muscle of the opposite limb should be similarly
palpated for comparison and to detect similar disease. Bear in mind that this muscle crosses
multiple joints, so that stretching of the muscle (i.e. elbow, carpal, and digit extension) may
result in a more pronounced pain response (Chapter 5), particularly if the level of injury is
proximal. Establishing a diagnosis generally involves palpation, and confirmation can be
accomplished by ultrasonographic examination of the muscle and tendons if the tendons are
accessible. This may confirm the diagnosis and can be helpful to describe the extent of the dis -
ease, potentially directing treatment strategies. Radiographs are used to detect associated bony
changes like avulsions, enthesiophytes, or dystrophic mineralization in chronically damaged
tissues. Magnetic resonance imaging, although seldom used for this condition, may provide
more detailed information.