Urinary excretion by dogs of intravenously administered simple sugars

Seven simple sugars, commonly used in intestinal function tests, were simultaneously administered intravenously to dogs and their urinary excretion was measured to assess their potential for metabolic degradation. Lactose, lactulose and 3-O-methyl-D-glucose were excreted unchanged, but small proportions of palatinose and sucrose were not, and were assumed to have been metabolised. More than half of the administered D-xylose and a quarter of L-rhamnose was not excreted and was assumed to have been metabolised. These findings may be significant for the interpretation of differential sugar absorption tests and the D-xylose tolerance test.