Page 188 - Canine Lameness

160 12 Distal Limb Region

DISTAL LIMB REGION

(A) (B) (C)

(D) (E) (F)
Figure 12.9 Pad conditions: (A) corns; (B) paw pad hyperkeratosis; (C) pad overgrowth from abnormal
weight-bearing; (D) pemphigus foliaceus; (E) superficial necrolytic dermatitis; and (F) digital pad ulceration.

on the pads (Figure 12.9A). Sight hounds, especially Greyhounds, are prone to developing these
lesions, perhaps because of the anatomical differences of these dogs compared to other breeds
(i.e. long narrow feet with little distance separating the digital pads). The lesions may be inci -
dental findings or may be painful and cause lameness. They occur most often (90%) on the digi -
tal pads of digits 3 and 4 of the thoracic limbs but can appear on the metacarpal and metatarsal
pads as well (Guilliard et al. 2010). Their etiology is not known but hypothesized to be caused
by scar tissue related to trauma or foreign bodies, or hypertrophy of the eccrine sweat glands
due to pressure (Balara et al. 2009). Controversy exists as to whether they may be a result of a
papilloma virus infection (Balara et al. 2009; Anis et al. 2016).
Clinical signs of corns frequently include lameness when walking on hard surfaces and
excessively long nails due to the animal shifting its weight proximally onto its metacarpal/
metatarsal pads to mitigate discomfort. Radiographs are used to rule out radiopaque for -
eign bodies. The diagnosis is made by visual inspection and pain response during palpation,