We have reported tab[et-induced focal esophagitis and esophageal stricture
formation in cats. The proposed mechanism is thought to be abnormal esophag
eal tablet retention resulting in focal esophagitis with subsequent strictu
re formation. The objective of this study was to evaluate the passage of ta
blets and capsules when given alone (dry swallow) and when followed by a wa
ter bolus (wet swallow) to determine if this could. in part, explain the es
ophageal stricture formation we have observed in cats. Fluoroscopy was used
to evaluate tablet or capsule passage after administration. The percentage
of dry tablet swallows that successfully passed into the stomach was 0.0%
at 30 and 60 seconds, 6.7% at 90 seconds, 13.3% at 120 seconds, 26.7% at 18
0 and 240 seconds, and 36.7% at 300 seconds. Wet tablet swallows successful
ly passed 90.0% of the time at 30 seconds, 93.3% of the time at 60 seconds,
and 100.0% of the time thereafter. The percentage of dry capsule swallows
that successfully passed was 16.7% at each time interval. Wet capsule swall
ows successfully passed 96.7% of the time at 30 seconds and 100% of the tim
e thereafter. For each time interval. wet swallows achieved significantly g
reater percentage passage into the stomach when compared to dry swallows (P
< .05). This study shows that tablets or capsules given by dry swallow hav
e prolonged retention in the esophagus compared to those given by wet swall
ow. On the basis of this study, we recommend the routine administration of
a water bolus to cats receiving tablets or capsules PO to facilitate esopha
geal clearance. This practice may help prevent medication-associated esopha
gitis or stricture formation.