Page 573 - Feline diagnostic imaging

32.2 Accuired one Disease 587

Figure 32.8 Lateral (a) and ventrodorsal (b) views of the pelvis. The caudal vertebrae are malformed and partially fused, resulting in
a shortened tail with a curved shape. This was thought to be developmental and classified as stumpy.

called complete when the digits are connected throughout portion of the ulna being missing and may be a hereditary
their entire length and incomplete when the digits remain trait in Siamese and domestic shorthair cats [1, 8, 25, 28].
partially separated. Radiographic changes can include
complete or incomplete fusion of phalanges and metatar- 32.2 Acquired Bone Disease
sal or metacarpal bones [1, 25, 26].
Ectrodactyly is the result of maldevelopment of the cen-
tral rays of the limb producing longitudinal splitting of the There are many acquired osseous diseases in cats. These
will broadly be classified into aggressive, traumatic, and
extremities. This is sometimes referred to as the “lobster miscellaneous etiologies.
claw defect.” This is also thought to be inherited as an auto-
somal dominant trait with variable expressivity. Feline 32.2.1 Aggressive Bone Disease
cases reported are between the first and second metacarpal
bones, but clefts between other metacarpals may occur. Part of the characterization of a bone lesion as aggressive is
This defect is often seen in combination with other anoma- dependent on the underlying radiographic appearance.
lies such as syndactyly. Most cases are unilateral and affect Aggressive lesions include neoplastic (primary, metastatic)
only the forelimb. and infectious (fungal or bacterial osteomyelitis) causes. A
Amelia is the congenital absence of one or more limbs definitive distinction between neoplastic and infectious
[1, 8, 25, 27]. Hemimelia is a congenital complete or partial bone lesions is extremely difficult as both will have charac-
absence of one or more bones. Radial hemimelia is the teristic aggressive changes. However, specific radiographic
most common type recognized in cats; it is usually unilat- features as well as the signalment, history, and exam find-
eral with variable absence of the radius (Figures 32.10 ings can be used to prioritize the diagnostic list. Biopsy is
and 32.11). This often occurs in conjunction with some typically required for definitive diagnosis.