Relationships between fecal consistency and colonic microstructure and absorptive function in dogs with and without nonspecific dietary sensitivity.
OBJECTIVE
To determine relationships between fecal consistency and colonic microstructure and absorptive function in dogs with and without nonspecific dietary sensitivity.


METHODS
12 dogs with nonspecific dietary sensitivity (affected) and 9 healthy dogs (controls).


METHODS
Affected dogs were fed 4 test diets and control dogs, 3 diets for 4 weeks each in a crossover design. Fecal consistency was assessed daily. At the end of each feeding period, electrolyte and water transport were assessed, and colonic biopsy specimens were obtained for histologic examination and measurement of crypt water uptake by use of confocal microscopy.


RESULTS
Feces were consistently looser in affected dogs. In control dogs, we detected net colonic absorption of sodium and chloride and secretion of potassium and bicarbonate. Absorption of sodium and chloride was less in affected dogs, compared with controls, indicating that electrolyte transport was disrupted in affected dogs. This disruption was accentuated during feeding of diets associated with significantly poorer fecal consistency (ie, loose feces). Fecal consistency was inversely correlated with crypt water absorption, which was reduced in affected dogs. Colonic crypts were shorter and less dense in affected dogs fed diets associated with poor fecal consistency, compared with affected dogs fed other diets or with control dogs.


CONCLUSIONS
Colonic transport function is a major determinant of fecal consistency in dogs. Dogs with nonspecific dietary sensitivity are particularly susceptible to diet-induced changes in absorptive function. Such changes are associated with damage to colonic microstructure, disrupted electrolyte transport, and failure to dehydrate luminal contents.
Rolfe
Vivien E
VE
Waltham Centre for Pet Nutrition, Waltham-on-the-Wolds, Melton Mowbray, Leicestershire, UK.
Adams
Colleen A
CA
Butterwick
Richard E
RE
Batt
Roger M
RM
D000821:Animal Feed; D000818:Animals; D001706:Biopsy / Q000662:veterinary; D003106:Colon / Q000378:metabolism* / Q000473:pathology; D003108:Colonic Diseases / Q000378:metabolism* / Q000473:pathology; D018592:Cross-Over Studies; D004283:Dog Diseases / Q000378:metabolism* / Q000473:pathology; D004285:Dogs; D004573:Electrolytes / Q000032:analysis; D005243:Feces / Q000166:cytology; D005512:Food Hypersensitivity / Q000378:metabolism* / Q000473:pathology; D007408:Intestinal Absorption / Q000502:physiology; D007413:Intestinal Mucosa / Q000166:cytology / Q000378:metabolism / Q000473:pathology
D004573:Electrolytes