Background and Aim: The efficacy of intranasal (IN) dexmedetomidine in cats as a premedication remains elusive. Thus, this study aimed to compare the perioperative and sparing effects of IN and intramuscular (IM) dexmedetomidine administration on propofol requirements for anesthetic induction in cats. Materials and Methods: This study randomly assigned 16 cats into two groups of IN or IM dexmedetomidine at 20 μg/kg. Sedation scores and side effects were recorded at time points of 0, 5, 10, 15, and 20 min after the dexmedetomidine administration. Anesthesia was induced with intravenous (IV) 1% propofol by titrating a bolus of 2 mg every 45 s and the total dose of the administered IV propofol to achieve endotracheal intubation was recorded. Results: Cats receiving IM dexmedetomidine were significantly associated with higher sedation scores. All cats were sedated at 20 min after premedication; however, the average composite sedation scores in the IN group were significantly lower than those in the IM group during premedication. Pre-operative side effects, including vomiting, were more frequently observed in the IN group (5 cats, 62.5%) than in the IM group (3 cats, 37.5%; p < 0.05). Higher body temperature (>1°F compared to baseline) was more frequently observed in the IN group (6 cats, 75.0%) than in the IM group (1 cat, 12.5%; p < 0.05). The dosage of required propofol in the IN group was significantly higher (1.1 ± 0.3 mg/kg) than that in the IM group (0.7 ± 0.2 mg/kg; p < 0.05). The duration of general anesthesia was comparable between the groups. Conclusion: IN dexmedetomidine produces moderate sedation and cats may have side effects, including vomiting and higher body temperature. Higher sparing effects of propofol were identified in the IM group compared with the IN group. Nonetheless, IN administration of dexmedetomidine provides a noninvasive alternative to the IM route.

Background and Aim: Intranasal (IN) sedatives provide a non-invasive route for premedication drug administration. This study compared the cardiorespiratory and sparing effects of IN dexmedetomidine combined with morphine (DM) or tramadol (DT) on alfaxalone requirements for anesthesia induction in cats. Materials and Methods: Twenty-four cats were randomly assigned to three groups: Dexmedetomidine combined morphine (IN dexmedetomidine 20 µg/kg plus 0.2 mg/kg morphine), DT (IN dexmedetomidine 20 µg/kg plus 1 mg/kg tramadol), or control (no premedication). The intravenous dose of 1% alfaxalone for endotracheal intubation was recorded with sedation scores, cardiorespiratory parameters (heart rate and respiration rate), and side effects. Results: Both DM and DT were associated with significantly higher sedation scores than baseline, and sedation scores were found to be highest 20 min after premedication. Sedation scores were comparable between DM and DT groups. Side effects, including hypersalivation, vomiting, and pupillary dilation, were observed in the DM and DT groups. The dosage of alfaxalone required in the DM group (1.5 ± 0.3 mg/kg) was comparable to that of the DT group (2.0 ± 0.6 mg/kg, p = 0.0861), and both groups required significantly less alfaxalone than the control group (3.0 ± 0.6 mg/kg; p < 0.01). Heart and respiratory rates were comparable between the DM and DT groups. Duration of anesthesia in the control group (11 ± 4 min) was significantly shorter than in the DM (29 ± 5 min, p = 0.0016) and DT (38 ± 14 min, p < 0.001) groups. Conclusion: Intranasal administration of DM or DT produces good sedation and offers an alternative, non-invasive route for cats undergoing general anesthesia. Keywords: alfaxalone, dexmedetomidine, intranasal, morphine, tramadol.