Small Animal Radiology and Ultrasound: A Diagnostic Atlas and Text

Chapter Three The Abd omen 325
Fig. 3-90 A 9-year-old male Giant
Schnauzer with vomiting for 1 week
and melena and hematemesis for 2
days. The ventrodorsal double-contrast
gastrogram (performed immediately
after a GI series that had
normal results) revealed an irregularly
oval structure outlined by a thin
line of barium just to the right of the
midline and on the caudal wall of the
stomach (solid white arrow). A similar
lesion is poorly outlined on the
cranial body wall of the stomach
(open white arrow). The pylorus is
tightly closed in this view and the
normal mucosal folds are coated
with barium. Diagnosis: Benign gastric
ulcers.
Pyloric outflow obstruction may be recognized during the ultrasonographic examination.
Symmetric or asymmetric thickening of the pylorus or a mass may be observed.
Hypertrophic pyloric gastropathy produces a uniform thickening of the hypoechoic muscular
layer of the pylorus. The extent of pyloric wall thickening varies from 9 to 19 mm,
with the thickness of the muscularis ranging from 3.0 to 5.4 mm. Gastric distention and
vigorous peristalsis were also observed. 343
A thickened gastric wall, thickened rugal folds, and loss or decreased definition of the
normal gastric wall layers were identified ultrasonographically in dogs with uremic gastritis.
A hyperechoic line identified at the mucosal-luminal junction was associated with gastric
mineralization. 344 Changes in the mucosal surface representative of ulcers also may be
identified by ultrasonography. 345
Foreign bodies may be identified using ultrasonography. Most foreign bodies will be
hyperechoic, will have sharply defined margins, and will have distal shadowing. 336,346
Foreign bodies will move readily within the stomach with changes in the patient’s position.
Chunks of dry dog food may have a similar appearance; however, their large number and
uniform size will make them easily recognizable.
Gastrogastric intussusception was identified during an ultrasonographic examination.
A spiraled, tapered echogenic mass was seen in the gastric fundus. The pyloric antrum and
the body of the stomach could not be identified. 328
PA N C R E A S
Density Changes. Pancreatic lesions are frequently difficult to define radiographically.
Although several radiographic findings have been described in association with pancreatitis,
it is our experience that none of the radiographic findings is reliably present and the absence
of these findings in any specific case should not preclude the diagnosis of pancreatitis. 347,348
The most commonly seen radiographic change is an apparent haziness and loss of detail in
the cranial right or middle abdomen. 349,350 This change must be interpreted cautiously,
because most animals have poor detail in this area due to the large number of contiguous and
adjacent fluid-dense structures. The proximal duodenum may be dilated and fixed in diameter
in response to the local inflammation. A similar rigidity may be observed in the gastric
wall adjacent to the left limb of the pancreas. In the ventrodorsal radiograph, the proximal
duodenum may be displaced toward the right lateral abdominal wall and the pylorus may be
displaced toward the midline. This widens the angle or curve between the pylorus and proximal
duodenum. The transverse colon may be displaced caudally away from the stomach and
may be either distended and fixed in diameter or completely empty. In severe pancreatitis,
there also may be a haziness throughout the entire abdomen (Fig. 3-94).