Sonography of the Normal Feline Gastrointestinal Tract

Abstract

The normal sonographic appearance of the stomach in various degrees of distension, the duodenum, the small intestine, and the large intestine was determined in awake and sedated cats. The mean stomach rugal fold thickness was 4.38 mm, and the interrugal thickness was 2.03 mm. No significant difference in stomach wall thickness was seen when the stomach was empty, half full, or full. The duodenal wall thickness was significantly greater than other parts of the small intestine, and this difference was accentuated by sedation (awake mean 2.4 mm; sedated mean 2.71 mm). The mean small intestinal wall thickness was 2.1 mm, and the mean colonic wall thickness was 1.67 mm. The five characteristic sonographic layers similar to that seen in the gastrointestinal tract of other species were routinely identified at all regions of the feline gastrointestinal tract.

Ultrasonographic evaluation of relative gastrointestinal layer thickness in cats without clinical evidence of gastrointestinal tract disease

“…[1][2][3][4][5][6] Variations in normal GI wall thickness in different GI segments (gastric fundus, body and pyloric antrum; duodenum; jejunum; ileum; colon) of the GI tract have been described in cats. 7,8 In one study conducted on 14 healthy cats, the duodenum wall was thicker when cats were sedated (mean, 2.7 mm) compared with when cats were awake (2.4 mm). 7 In another study conducted on 11 healthy cats, the ileum wall was thicker (mean, 2.8 mm) than all segments of the GI tract (gastric fundus, 2.0 mm; pylorus, 2.1 mm; duodenum, 2.2 mm; jejunum, 2.3 mm; and colon, 1.5 mm).…”

Treatment of pyloric stenosis in a cat via pylorectomy and gastroduodenostomy (Billroth I procedure)

“…The pylorus lies slightly more on the midline in cats than in dogs, with gastric wall thickness measuring between 1.1 and 3.6 mm. 8 Measurements may be greater if obtained when Figure 1 obtained at the juncture of the submucosa and tunica muscularis. Immunostaining (dark brown) demonstrates irregular smooth muscle bundles and likely myofibroblasts at the juncture of thickened tunica muscularis and submucosa.…”

Gastrointestinal Tract

“…Note the thick hyperechoic submucosa layer commonly seen because of fat deposition (between arrows), which differs from dogs. 17 In the cat, interrugal thickness has been reported as approximately 2 mm, 18,19 and rugal fold thickness as 4.4 mm. A portion of the left lobe of the pancreas is seen to the right of the stomach (PANC).…”

“…Hypoechoic mucosal folds represent rugae. 18 Gastric wall thickness is measured from the hyperechoic mucosal surface to the outer hyperechoic serosal layer of the stomach. B, A more longitudinal view through the body of the stomach shows an elongated rugal fold (R) with the appearance of gastric wall thickening.…”

“…The small intestine normally averages one to three peristaltic contractions per minute. 18,19,21 The duodenal papilla in the cat varies from 2.9 to 5.5 mm in width and has a maximum thickness of 4 mm on the transverse view. The duodenal papilla can sometimes be identified with a high-resolution transducer (see .…”