Fig. 46.2 Normal position of the stomach in a dog as illustrated by the position of the gastric axis in different
patient positions. A, Right lateral view of the abdomen of the dog. The gastric axis is parallel with the ribs. B,
Left lateral view of the same dog. The gastric axis is perpendicular to the spine. C, Ventrodorsal view of the
same dog. The gastric axis is mildly cranially angled and nearly perpendicular to the spine.
Fig. 46.3 Normal position of the stomach in a cat. A, Right lateral view of the abdomen of the cat. The gastric axis is parallel with the ribs. B, Ventrodorsal view of the same cat. The stomach is acutely angled with the pylorus located on midline to slightly to the left of midline (arrows).
Fig. 46.4 Gastrograms illustrating the normal positions of the stomach with the patient in dorsal recumbency.
A, Ventrodorsal view of a dog. The gastric axis of this dog is approximately perpendicular to the spine. B,
Ventrodorsal view of a cat. The stomach is acutely angled with the pylorus located closer to midline than in
the dog; this is a consistent species difference.
Fig. 46.6 Normal variations in ﬂuid (barium) and gas distribution in the stomach with different patient
positions. A, Dorsoventral view, in ventral recumbency. Gas rises to the fundus and ﬂuid settles dependently
to fll pyloric portions and part of the body. B, Ventrodorsal view, in dorsal recumbency. Gas is located in the
body and pyloric antrum. Fluid settles dependently to fll the fundus and body. In this dog, there is a small
amount of barium trapped in the pyloric antrum. C, Left lateral view. Gas rises to the pyloric portion, and
ﬂuid settles dependently to fll the fundus and body. D, Right lateral view. Gas rises to the fundus and body,
when there is some barium adherent to the mucosa. Fluid settles dependently to fll the pyloric portion.
Fig. 46.12 Cranial gastric displacement from a small liver secondary to a portosystemic shunt. The pylorus
and body are displaced cranially on lateral (A) and ventrodorsal (B) views. In B, the fundus-pylorus angle is
abnormal, with the pylorus being located more cranially than normal.
Fig. 46.13 Gastric displacement caused by hepatomegaly. A, Lateral view. The pylorus (black arrows) is
displaced caudally by an enlarged liver (L), and the fundus-pylorus axis (black line) is no longer parallel with
the ribs. B, Ventrodorsal view. The pylorus (black arrows) is displaced caudally and to the left, and the fundus
pylorus axis (black line) is no longer transverse.
Fig. 46.14 Ventrodorsal radiograph of a dog with a large pancreatic abscess. Barium has been administered. The pylorus is displaced to the left and cranially. The cranial duodenal ﬂexure and proximal part of the descending duodenum have a broad arc around the cranial surface of the mass, which itself is not visible.
Fig. 46.15 Ventrodorsal radiograph of a dog with an acquired left-sided diaphragmatic hernia that has allowed the fundus to shift cranially. Although there are no gas-containing bowel segments in the pleural space, the cranial position of the stomach is diagnostic for a hernia.
Fig. 46.16 Sliding hiatal hernia (type 1 hiatal hernia) in dog, which was presented for further evaluation of
a previously detected right caudal lung mass. A, Right lateral radiograph. The stomach is in relative normal
position. B, Left lateral radiograph. The stomach is cranially positioned, but persistently summating mostly with
the left crus of the diaphragm. The rugal folds are well visualized helping to identify the soft tissue structure
as the stomach. A lung mass is noted in the ventral aspect of the right caudal lung lobe (white arrow). C, Left
lateral radiograph after the dog coughed. The fundus and part of the body of the stomach are displaced cranially
and summating with the dorsocaudal thorax. The esophagus and descending duodenum are dilated and gas
Fig. 46.17 Peritoneopericardial hernia in a cat. A, Right lateral radiograph. The cardiac silhouette is enlarged
and has an irregular shape. Irregular gas opacities are noted summating with the cardiac silhouette. Effacement
of the ventral diaphragmatic border is present. A large region of gas is superimposed on the liver. The thoracic
spine has an undulating shape. B, Dorsoventral radiograph. The pylorus and part of the body of the stomach
are displaced cranially and located within the pericardium
Fig. 46.18 Gastrogastric intussusception in a
4-year-old mixed breed dog with acute vomiting.
A, Right lateral, B, Left lateral and C, Dorsoventral
radiograph of the abdomen. A large soft tissue
opacity is noted extending from the pylorus area
towards the luminal aspect of the pylorus to body
of the stomach. In the most left lateral and central
aspect of this soft tissue mass a small indentation
Fig. 46.18, cont'd D, Ventrodorsal and E, Right lateral radiograph of the abdomen post negative gastrography.
The luminal soft tissue mass extending from the pylorus area is unchanged present and partially surrounded
by a small rim of gas. In the pylorus area, the mass cannot be differentiated from the gastric wall. In the body
of the stomach, the mass is well differentiated from the gastric wall. Surgery confrmed a gastrogastric intus
susception, in which the antrum of the stomach extended into the body of the stomach. The duodenum was
not involved in the intussusception. (Courtesy of DoveLewis Emergency Animal Hospital, Portland, Oregon).
Fig. 46.19 Acute gastric gaseous dilation in a cat with severe respiratory distress due to severe cardiogenic
edema secondary to hypertrophic cardiomyopathy and left sided heart failure. A, Right lateral and B, dorsoventral
radiograph. The stomach is predominately gas flled and mildly to moderately dilated due to aerophagia. A diffuse unstructured interstitial lung pattern is noted in the caudal lung lobes.
Fig. 46.20 Gastric dilation without volvulus. A, Left lateral view. Gas is present in the pyloric antrum (P, black arrows) and body (B, white arrows) of the stomach as expected. The narrowing between the body and pyloric antrum is a peristaltic contraction. B, Right lateral view. The fundus (F,
white arrows) is extremely distended. There is a small amount of gas trapped in the pyloric antrum (black arrows). The distribution of gas as a function of left versus right recumbency is as expected in a normal subject, indicating that the stomach is not rotated, unless the rotation is 360 degrees, which is unusual.
Fig. 46.21 Massive pneumoperitoneum secondary to intestinal perforations due to ballistic trauma. Left lateral radiograph. A large, round ovoid gas opacity is present in the cranial abdomen (black arrows). This should not be confused with acute dilation or volvulus of the stomach. The stomach
is located in correct position in the cranial abdomen (white arrowheads), easily identifed by the presence of rugal folds. The lack of serosal detail is secondary to the presence of peritoneal ﬂuid due to severe chronic peritonitis.
Fig. 46.22 Gastric volvulus. A, Left lateral view. The stomach is moderately distended with gas in the fundus (black arrows). This is easily misinterpreted as gas in the pylorus, as expected in the left lateral view. B, Right lateral view. The ﬂuid shifts into the fundus (F), and gas outlines the pyloric
portion (P) as well as the body (B). The compartmentalization (black arrows) between the pylorus and body, and the characteristic appearance of the pylorus in the dorsocranial aspect of the abdomen, indicate that the pylorus is on the left and the fundus is on the right and that there is a
gastric volvulus. Note the malpositioned and slightly enlarged spleen (S). The spleen will follow the fundus because of anatomic connections.
Fig. 46.23 Left (A) and right (B) lateral views of a dog with acute gastric dilatation. On the basis of these
radiographic fndings, the pylorus and the fundus are positioned normally. A gastric tube could not be passed
into the stomach. Final diagnosis was 360-degree gastric volvulus.
Fig. 46.24 Lateral radiograph of a dog with gas in the wall of the pyloric antrum (white arrows).
Fig. 46.25 Lateral (A) and dorsoventral (B) radiographs of a dog with ﬂuid-flled gastric distention caused
by chronic pyloric obstruction. The stomach is more diffcult to identify when flled with ﬂuid instead of gas.
The caudal margin of the stomach is indicated in A by the white arrows and in B by the black arrows. In A,
some opaque gastric contents have settled into the dependent pyloric region of the stomach (black arrow).
Fig. 46.26 Ventrodorsal radiograph 10 hours after barium was given. The stomach is distended (white arrows) with intraluminal gas and ﬂuid and some of the barium. There should be no residual barium after 10 hours and this, along with the distention, is indicative of gastric outﬂow obstruction.
Fig. 46.27 A, Ventrodorsal radiograph of the pyloric region of a dog with restrictive disease of the pylorus.
The string sign (black arrow) is caused by barium that flls the length of the lumen of the narrowed pyloric
sphincter because of an annular type of stricture. B, Ventrodorsal radiograph of the pyloric region of another
dog with restrictive disease of the pylorus. The peristaltic pouch (black arrow) is the outpouching of the pyloric
antrum along the lesser curvature as a peristaltic wave pushes contrast medium up against the mass-type lesion
encircling the pylorus. A pronounced delay in gastric emptying was also present.
Fig. 46.28 Ventrodorsal oblique radiograph of the pylorus of a dog with obstructive disease of the pylorus. A hemispheric flling defect is at the pylorus that projects into the lumen (black arrows). Pronounced delay in gastric emptying was present.
Fig. 46.29 Longitudinal ultrasonogram of pyloric stenosis. The pylorus wall is moderately thickened. The layered appearance of the pylorus wall is still present; the muscularis is markedly thickened and the luminal aspect of the pylorus wall is irregular. Caudal is to the right, and ventral is to the top.
Fig. 46.30 Lateral radiograph (A) of a dog
with a discoid metallic gastric foreign body.
Determining the type of coin is important based
on the association of zinc toxicity with some
coin types. This object is likely a U.S. dime,
based on the markings (B) that resemble the
engraving present on that particular coin
(arrows) (C). The magnifcation-corrected
diameter of the coin was also identical to that
expected for a U.S. dime.
Fig. 46.31 Lateral (A) and ventrodorsal (B) radiographs of a dog with a large gastric foreign body. This
radiopaque material is easy to visualize because of the large amount of gas surrounding the foreign body, which
was aggregated leaves and plant material. Expansion of ingested polyurethane glue can also lead to a similar
Fig. 46.32 A ball in the pyloric portion of the stomach (black arrows) is diffcult to see on the right lateral
view (A) because of ﬂuid in the pylorus. In B, gas has been administered by a gastric tube, making the ball
(black arrows) easier to see. Note the ball has moved to the fundus.
Fig. 46.33 A, Ventrodorsal oblique radiograph of the stomach of a dog with a gastric ulcer (black arrow).
The flling defects protruding into the stomach (white arrows) represent the collar of the ulcer. B, Sagittal
sonogram of the stomach of another dog. The pyloric region of the stomach is thickened, and layers are not
identifable. The white arrow indicates a portion of the stomach wall that is focally thinner than the remainder.
The mucosal surface of this area is hyperechoic. A large ulcer was found in this area at necropsy; the diagnosis
Fig. 46.34 A, Ventrodorsal barium gastrogram of a cat. A smooth flling defect is present from a mass along
the greater curvature (black arrowheads). B, Ventrodorsal barium gastrogram of a dog. An annular mass encircles
the pyloric portion and part of the body. This area failed to distend, and the abnormality persisted throughout
the study. Final diagnosis was gastric adenocarcinoma.
Fig. 46.35 Longitudinal ultrasonograms of gastric neoplasia. A, Lymphosarcoma in the stomach wall of a cat.
The stomach wall is thickened and hypoechoic and has lost the normal layered appearance. B, Suspected adeno
carcinoma in the stomach wall of a dog. The wall is thickened uniformly and decreased in echogenicity. The
normal layered appearance is disrupted. Caudal is to the right, and ventral is to the top.
Fig. 46.36 Lateral survey radiograph of the abdomen of a cat with a thick gastric wall. The thickened wall is best visualized in the ventral midabdomen and is associated with a narrow, tubular, gas-flled lumen.
Care should be taken when evaluating the stomach wall on survey radiographs because ﬂuid in the lumen can silhouette with the wall, creating a false impression of wall thickening.
Fig. 46.37 Close-up ventrodorsal radiographs of a dog with gastric mineralization secondary to chronic renal failure. Thin, curvilinear, mineral ized opacities that parallel the rugal folds of the stomach are caused by gastric calcifcation.
Fig. 46.39 Right lateral radiograph of a dog with leakage at the site of the placement of the percutaneous
endoscopic gastrostomy (PEG) tube. The PEG tube was placed to support adequate nutrition as the patient
was not gaining weight and had recurrent pneumonia due to severe megaesophagus. Iodinated contrast medium
was administered through the tube and leakage of contrast medium at the level of the gastric wall was present
(arrows). The stomach has an abnormal shape, which is commonly seen post gastric tube placement or