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Chapter 25

Hedgehogs

Hedgehogs are unique among mammalian cage pets III NORMAL RADIOGRAPHIC ANATOMY
in two principal ways: (1) the dorsal half of their body
is covered by a thick coat of long protective spines The skull and teeth of a hedgehog differ decidedly
(Figure 25-1), and (2) when threatened, hedgehogs roll (Figure 25-7) from those of the preceding small
into a tight ball, exposing nothing but their formidable mammals because the hedgehog is an insectivore
spines (Figure 25-2). (insect eater) while the others are Rodentia, or gnawing
By comparison, the ventral half of the hedgehog mammals.
body is only covered by a short coat of hair and is The torso of a hedgehog is encased by a thick layer
spineless. When viewed from the underside, a hedge- of fat, especially before beginning hibernation. This,
hog is nearly unrecognizable (Figure 25-3). along with their diminutive size, can make assessment

of the thoracic interior quite difficult, with respect to
evaluating the size and shape of the heart and evaluat-
III RADIOGRAPHY ing the lung for abnormal density (Figure 25-8). Radio-
graphic diagnosis is further compromised when the
limbs are superimposed on the torso as they are in the
Nonchemical, Nongas Restraint
lateral projection made with a horizontally directed
As with most small mammalian cage pets, hedgehogs x-ray beam (Figure 25-9).
can be radiographed with or without chemical or gas
restraint. When poor condition, illness, or injury make
anesthesia unacceptably risky, hedgehogs can be radio- III INJURIES
graphed without direct manual restraint by placing
them in an adjustable corral constructed of individual Injuries sustained by hedgehogs are comparable to
foam panels (Figure 25-4). A wooden spatula, which those that occur to other small mammalian cage pets,
is radiographically transparent, is used to keep the for example, bruises, cuts, fractures, sprains, and dis-
animal still during the exposure (Figure 25-5). By locations. Crush injuries, especially those to the chest,
moving the x-ray tube from its usual vertical position often prove fatal. Deep bite wounds to the head, throat,
into a horizontal, cross-table position, it is possible to and neck are capable of causing very serious injuries
obtain both dorsoventral and lateral projections and death caused by blood loss and resulting shock. A
without moving the animal. sudden, large volume pneumothorax is extremely dif-
fi cult to treat and hard to effectively monitor.
Gas Anesthesia
Alternatively, an anesthetic gas administered by mask III ABDOMINAL DISEASE:
is used to restrain a hedgehog while it is being radio- A DIAGNOSTIC STRATEGY
graphed (Figure 25-6). Typically, the animal arrives
in radiology fully conscious, is masked down, radio- Perhaps the single most effective strategy for diagnos-
graphed, and then recovers while still in radiology. ing abdominal disease in small mammals such as
The entire process can often be done within 10 hedgehogs is assessment of the bowel distribution
minutes. Text continued on p. 288.
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