It has been hypothesized that cribbing, the equine oral stereotypy, may increase salivary production
and, therefore, reduce gastric acidity in a species prone to gastric ulcers. To test the hypothesis
that cribbing stimulates salivary secretion, parotid salivary duct fistulas were surgically created in 2
horses. In the first experiment, saliva was collected while the number of crib bites was counted. There
was no significant relation (r2 5 0.022) between the numbers of crib bites and the volume of saliva
produced. The second experiment involved measuring salivary output when one horse was cribbing
and when he was eating, but could not crib. Before feeding, the horse produced 1 (0-2) mL of saliva
while displaying 20 crib bites. The horse produced 31 (2-212) mL of saliva while eating 200 g of grain.
After eating, the horse produced 2 (1-10) mL of saliva while displaying 20 crib bites. There was a significant
difference in saliva production associated with eating (Kruskal–Wallis statistic 5 12.42, P ,
0.02). Fifteen to 30 times more saliva was produced while eating than while cribbing. These preliminary
findings indicate that in those 2 cribbing horses, saliva production was not increased during cribbing,
thereby questioning the hypothesis that saliva production during cribbing leads to decrease in
gastric acidity.