Normal ultrasonographic reference values for the gastrointestinal tract in developing puppies.

Thickness of the individual layers of the wall of the stomach, duodenum, jejunum and colon was assessed by means of ultrasonography in developing puppies at 4, 8 and 16 weeks of age. Reference intervals for the thickness of individual ultrasonographic layers of the stomach, duodenum, jejunum and colon at different ages are reported. An increase in wall thickness of all the examined gastro-intestinal tracts in relation to age was recorded. The effect of body-weight was stronger on duodenal and jejunal thickness whereas it resulted lesser on stomach and colon. Correlation between duodenal and jejunal mucosal layer thickness and body weight was strong, while correlation between body weight and the other intestinal wall layers of the duodenum, jejunum and colon ranged from moderate to weak. No effects of gender were detected.