Science Digest: What is the most effective dose of medetomidine for the induction of emesis in cats?

12 November 2025

Various drugs are used to induce emesis in cats. Medetomidine has been used empirically, but there are no data on the emetic effect or the most effective emetic dose of medetomidine.

A new study published in the Journal of Feline Medicine and Surgery has evaluated the emetic effect and the most effective dose of medetomidine in cats after ingestion of foreign material.¹

The study included 58 cats presented to Ludwig-Maximilians-University Munich after foreign material ingestion, which had emesis induced. Cats were excluded if they had ingested material for which emesis is contraindicated, their mental status was altered due to signs of poisoning, or they had severe underlying diseases.

Cats were randomly assigned to one of four groups and received either 10, 20, 30, or 40 µg/kg of medetomidine administered intramuscularly (IM) after ingestion. The success rate, frequency, and time to emesis, sedation scale score, and adverse effects were recorded for all groups. If induction of emesis was not successful after administration of 10 or 20 µg/kg medetomidine, a second bolus of medetomidine (20 µg/kg IM) was administered. A clinical examination was undertaken 20 minutes after the last bolus of medetomidine.

Foreign materials ingested were plants, mostly lilies (16 out of 58 cats), linear foreign bodies (15/58), human food such as chocolate, raisins or grapes (12/58), and human drugs (3/58). Median time from foreign material ingestion to presentation was 60 minutes (range 7–900 minutes).

Emesis induction was successful with a dose of 10–40 µg/kg of medetomidine in 62.1% of the cats, with the highest success rate (76.5%) achieved with 20 µg/kg. For non-vomiting cats, the success rate increased to 88.2% after a second injection of 20 µg/kg medetomidine 10 minutes after the first. The success rates were lower for other doses, at 53.3% for 10 µg/kg, 62.5% for 30 µg/kg, and 50% for 40 µg/kg. Although more cats vomited after being given 20 µg/kg, no statistically significant difference in the emesis success rate was found between the different doses, most likely due to the small number of cats included.

The median time to emesis after the first injection of medetomidine for all cats was 5 minutes (range 3–14 minutes), and this was significantly different between groups, varying from 7.5 minutes with 10 µg/kg and 3 minutes with 40 µg/kg. The median frequency of emesis after the first injection for all cats was 1 (range 0–5).

The most common adverse effect was sedation. The median sedation score for all cats was 12 (range 1-19), and it increased with increasing doses of medetomidine, with the highest sedation score occurring with a 40 µg/kg dose. The only other adverse effect was bradycardia, occurring in 6.9% of cats and lasting a few minutes. Medetomidine was antagonised with atipamezole in cats who were moderately or severely sedated (81% of cats).

Limitations of the study are the small number of cats included; the possibility that cats that had a longer duration from foreign material ingestion to presentation may no longer have had material in the stomach, leading to unsuccessful emesis attempts; and the possibility that adverse effects occurred after the cats were discharged.

Take home message

Medetomidine is effective for inducing emesis in cats, with a comparable success rate to xylazine and dexmedetomidine, and is therefore a feasible alternative for clinical use. The dose with the highest emetic effect and the least adverse effects was 20 µg/kg of medetomidine (IM).

Read the full paper:

¹Sänger F & Dörfelt R (2025) Evaluation of different doses of medetomidine for the induction of emesis in cats. Journal of Feline Medicine and Surgery. 27(9). doi:10.1177/1098612X251367617