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Chapter 28

Skunks, Squirrels, Raccoons,

and Armadillos

Raccoon
The small collection of animals in this chapter does not
constitute a taxonomic alliance but rather is a grouping Morphologically and radiographically, the chest and

of convenience. The first three, skunks, squirrels, and abdomen of raccoons resemble those of dogs (Figure
raccoons, are often found in rural areas, on the fringes 28-3).
of suburbia, and in larger urban parks. Our usual
contact with such animals is through the Society for Armadillo
the Prevention of Cruelty to Animals (SPCA), when
the SPCA brings an injured animal to us for fi rst aid. Undoubtedly, the reader is wondering why armadillos
Good Samaritans sometimes bring us orphaned young have found their way into these pages, given the length
to be cared for until a permanent home can be found. and severity of our western Canadian winters, and the
Occasionally, we receive pet skunks or raccoons for a fact that their nearest natural habitat is nearly 2000
variety of ailments. miles away. I spent a year in Texas while on sabbatical
and all too regularly encountered this unusual animal
lying on the roadside as I made my daily journey to
III NORMAL RADIOGRAPHIC ANATOMY and from the university. Since that time I have rarely
had the opportunity to radiograph an armadillo, so
clearly I am not an expert, but I could not resist the
Squirrel
opportunity to show and comment briefly on their

The skull of the squirrel is its most distinctive feature fascinating radiographic anatomy.
when comparing it with other comparably sized mam- The overlapping protective plating of the armadillo,

mals. In lateral profile, the skull resembles the egg of termed the carapace, gives the exterior surface of the
a small bird, symmetrically rounded caudally and animal a highly distinctive saw-toothed appearance.
tapered rostrally. Otherwise, squirrels resemble other The carapace nearly reaches the cranium, which is dis-
small rodents, except for their long bushy tails (Figure proportionately small compared to the trunk, and lies
28-1). much further dorsal to the cervical spine than might
be imagined. The thorax occupies considerably less of
the total trunk length than it does in cats and dogs, an
Skunk
appearance accentuated by its abbreviated sternum.
The chest of a skunk resembles that of a dog, with the The heart of an armadillo appears quite rounded in
exception of the heart, which appears much rounder. a lateral projection, its caudoventral border frequently
Both standard projections appear to show left-sided concealed by the overlapping diaphragm. In the same
emphasis as one might expect with mitral insuffi ciency; view, a pronounced angle typically exists where the
however, this is normal in a skunk (Figure 28-2). diaphragm meets the sternum, falsely suggesting a
Because of an ample coat of perithoracic fat, the sternal fracture or diaphragmatic hernia. These appear-
lung of skunks often appears increased in density and ances are accentuated by expiratory fi lming (Figure

decreased in detail, mimicking pleural fluid or pneu- 28-4).
monitis. Extrathoracic fat folds can be quite prominent The abdomen of an armadillo is rendered radio-
in the dorsoventral or ventrodorsal projections. graphically unique by its armored plates, which
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