Ultrasonographic assessment of the effect of metoclopramide, erythromycin, and exenatide on solid-phase gastric emptying in healthy cats

Background: Available data on the effect of gastrointestinal motility-modifying drugs in cats are limited. Most recommendations for drug usage and dosage are based on collective clinical experience.

Objectives: To assess the effects of metoclopramide, erythromycin, and exenatide on gastric emptying (GE) and gastric motility in comparison to placebo. We hypothesized that metoclopramide and erythromycin would have prokinetic gastric effects, whereas exenatide would prolong GE times and decrease the motility index (MI) of antral contractions.

Animals: Eight healthy domestic shorthair cats.

Methods: Each cat had 4 separate ultrasonographic assessments. In a prospective, randomized, double-blind, 4-way crossover design, cats received placebo, metoclopramide, erythromycin, or exenatide for 2 days followed by a minimum 5-day washout period. Ultrasonographic GE times and MI were compared to placebo.

Results: When compared to placebo, the rate of GE was significantly faster after administration of metoclopramide and erythromycin. Significant differences were found at all fractions of GE after administration of erythromycin and all but 1 fraction after metoclopramide when compared to placebo. The rate of GE in the first half of the GE curve was significantly slower after exenatide administration. The total area under the Ml curve was significantly larger after administration of metoclopramide and erythromycin than after placebo.

Conclusions and clinical importance: Metoclopramide and erythromycin shorten GE times and increase the MI of antral contractions, thus having a prokinetic effect in the stomach of healthy cats, whereas exenatide causes an initial delay in GE.