Influence of age and body size on intestinal permeability and absorption in healthy dogs.
OBJECTIVE
To evaluate effects of age and body size of dogs on intestinal permeability (unmediated diffusion) as measured by the ratio of urinary lactulose to L-rhamnose (L:R) and absorption (carrier-mediated transport) as measured by the ratio of urinary D-xylose to 3-O-methyl-D-glucose (X:MG) and to determine whether these variables correlated with fecal quality.


METHODS
6 Miniature Poodles, 6 Standard Schnauzers, 6 Giant Schnauzers, and 6 Great Danes.


METHODS
A solution that contained lactulose and rhamnose or xylose and 3-O-methyl-D-glucose was administered orally to dogs that were 12, 22, 36, and 60 weeks old. Urine was collected 6 hours later, and urinary L:R and X:MG were calculated. Fecal moisture and scoring were recorded during the same periods.


RESULTS
Age and breed did not affect intestinal absorption, and we did not detect a relationship between X:MG and fecal variables. In contrast, we detected significant effects of age and body size on intestinal permeability. Puppies (12 weeks old) and large dogs had higher intestinal permeability than adult (60 weeks old) and small dogs. The increased intestinal permeability in large dogs was associated with lower fecal quality as indicated by the significant positive correlations between L:R and fecal moisture (r, 0.61) and L:R and fecal scores (r, 0.86) in adult dogs.


CONCLUSIONS
These results indicate that age and body size should be considered when assessing intestinal permeability by use of the L:R urinary excretion test in dogs. High intestinal permeability could be a possible cause of poor fecal quality in large dogs.
Weber
Mickaël P
MP
Laboratory of Nutrition and Endocrinology, National Veterinary School of Nantes, France.
Martin
Lucile J
LJ
Dumon
Henri J
HJ
Biourge
Vincent C
VC
Nguyen
Patrick G
PG
D000375:Aging / Q000502:physiology*; D000818:Animals; D001823:Body Composition; D004285:Dogs / Q000145:classification / Q000502:physiology*; D005260:Female; D006262:Health; D007408:Intestinal Absorption / Q000502:physiology*; D007422:Intestines / Q000502:physiology*; D010539:Permeability