This study investigated the prokinetic effect of metoclopramide and mirtazapine on gastric transit time (GTT), small bowel transit time (SBTT) and gastrointestinal transit time (GITT) during capsule endoscopy in four healthy beagle dogs. Four beagle dogs participated in the experiment as four groups at intervals of more than three days as the following: Control group 1 (capsule alone), Control group 2 (capsule alone), Metoclopramide administered group (metoclopramide + capsule) and Mirtazapine administered group (mirtazapine + capsule). The results of this study demonstrated there was no significant difference in GTT ([min] control group 1: 105 ± 90, control group 2: 172.5 ± 102 vs metoclopramide administered group: 247.5 ± 93, p = 0.07, 0.10) and SBTT ([min] control group 1: 120 ± 88, control group 2: 75 ± 39 vs metoclopramide administered group: 37.5 ± 15, p = 0.20, 0.18) for capsule only administered groups (control group 1 & 2) compared to metoclopramide administered group. In addition, there was no significant difference in GTT ([min] control group 1: 105 ± 90, control group 2: 172.5 ± 102 vs mirtazapine administered group: 127.5 ± 45, p = 0.56, 0.36) and SBTT ([min] control group 1: 120 ± 88, control group 2: 75 ± 39 vs mirtazapine administered group: 157.5 ± 38, p = 0.29, 0.07) between capsule only administered groups (control group 1 & 2) and mirtazapine administered group. In this study, the fact that metoclopramide might be ineffective and administration of mirtazapine might be inadequate in dogs were confirmed.