Page 193 - Canine Lameness

12.9 ­ctrF ­ onDcD oe ofofracDoe ctrs Decral Dimb reD o 165

resultant foot mutilation, poor or nonhealing wounds, and profound atrophy of the soft tissues
including muscles and tendons, with resultant osteopenia of the underlying bones of the affected
region. It is important that the attending clinician performs a careful neurological examination to
identify such conditions. DISTAL LIMB REGION

12.9.2 Dysostoses

Dysostoses are constitutional bone diseases characterized by abnormal development of individual
bones, or parts of bones. Examples of dysostoses include hemimelia (the congenital absence of a
part or all of one or more bones), dimelia (the duplication of the whole or part of limb), ectrodac-
tyly (congenital split formation or separation between metacarpal bones, also called “split-hand
deformity”), polydactyly (the occurrence of one or more extra digits), and syndactyly (the partial
or complete lack of separation between adjacent digits). Each of these conditions can cause lame-
ness. Diagnosis is made through clinical examination and confirmed with radiographs. Treatment
of these conditions depends on the severity of the disease and the clinical symptoms and may
include surgical correction (Towle-Millard and Breur 2018).

12.9.3 Hypertrophic Osteopathy
Hypertrophic osteopathy, also called Marie’s disease or hypertrophic pulmonary osteoarthropa -
thy, is characterized by the proliferation of periosteal new bone of especially the distal extremi -
ties (Figure 12.11). These distinct osseous changes are generally bilaterally symmetrical and
involve all four limbs. They occur secondary to a separate disease process within the thorax or

(A) (B) (C)

Figure 12.11 Hypertrophic osteopathy: (A, B) radiographs of the thoracic limb show smooth and irregular
palisading periosteal reaction along the cortices of the long bones (white arrows) with associated soft
tissue swelling; (C) chest radiographs reveal an extrapleural thoracic wall mass (black arrow) and
pulmonary nodules. The dog had previously received a thoracic limb amputation for treatment of
appendicular osteosarcoma.