Ultrasonographic evaluation of the thickness of the wall layers in the intestinal tract of dogs.

Objective: To ultrasonographically measure the thickness of the individual wall layers of the duodenum, jejunum, and colon of dogs.

Animals: 85 dogs with no clinical signs or ultrasonographic evidence of gastrointestinal tract disease.

Procedures: Total wall thickness and thickness of the mucosa, submucosa, muscularis, and serosa were measured ultrasonographically in the duodenum, jejunum, and colon of each dog.

Results: The mucosal layer was the thickest layer of the duodenum and jejunum. There was a significant difference in thickness of the mucosal layer between small and large dogs. Mean ± SD thickness of the mucosal layer of the duodenum for small, medium, and large dogs was 2.4 ± 0.5 mm, 2.6 ± 0.6 mm, and 2.8 ± 0.5 mm, respectively. Mean ± SD thickness of the mucosal layer of the jejunum for small, medium, and large dogs was 1.8 ± 0.4 mm, 2.0 ± 0.4 mm, and 2.2 ± 0.5 mm, respectively. The remaining wall layers of the duodenum and jejunum were similar in thickness, and there were no significant differences among small, medium, and large dogs. All layers contributed equally to the total colonic wall thickness. Mean ± SD thickness of the colonic wall for small, medium, and large dogs was 1.5 ± 0.3 mm, 1.4 ± 0.5 mm, and 1.6 ± 0.4 mm, respectively.

Conclusions And Clinical Relevance: Values for thickness of the wall layers of the duodenum, jejunum, and colon of dogs reported here may be useful for assessing gastrointestinal tract diseases primarily targeting a specific wall layer.