Xylazine & Induction of Emesis in Cats

In the Literature

Thies M, Bracker K, Sinnott V. Retrospective evaluation of the effectiveness of xylazine for inducing emesis in cats: 48 cats (2011-2015). J Vet Emerg Crit Care. 2017;27(6):658-661.

The Research …

There are important differences between dogs and cats with regard to inducing emesis for suspected toxin or foreign body ingestion. Although apomorphine or hydrogen peroxide are often used in dogs, these are generally ineffective in cats and may be harmful. Based on relative receptor density in the chemoreceptor trigger zone, α₂-adrenergic agonists (eg, xylazine, dexmedetomidine) have been recommended instead, although there is relatively little clinical evidence supporting their use. This retrospective study sought to assess the efficacy of xylazine for inducing emesis in cats and determine the rate of complications associated with administration.

Medical records from a referral center from 2006 to 2015 reviewed clinical characteristics of cats receiving xylazine for emesis induction after known or suspected toxin or foreign body ingestion. Forty-eight cats were included in the study, with an even split between known/suspected toxin exposure (n = 24) versus foreign body ingestion (n = 24). Xylazine was administered at a median dose of 0.49 mg/kg IM. Emesis was achieved in 60% (29/48) of patients; the aim of emesis (ie, recovery of foreign body or decontamination) was successful in 72% of these patients. Adverse effects were noted in 33% (16/48) of cats, with sedation being the most common (15/16); one of these cats also experienced pytalism. Another cat experienced bradycardia alone. Almost all (46/48) of the cats received a reversal agent; most (37/46) received yohimbine, whereas the remainder (9/46) received atipamezole. No differences were found with regard to age, sex, breed, reason for induction of emesis, or the occurrence of adverse effects between those that successfully vomited and those that did not.

… The Takeaways

Key pearls to put into practice:

• Xylazine at 0.5 mg/kg may be effective in inducing emesis in approximately 50% of feline foreign body or intoxication cases, with approximately three-fourths of those patients successfully expelling the ingested toxin or foreign body. Dexmedetomidine has also been shown to be effective in this regard and, in one study, was found to be superior to xylazine.¹

• The most common adverse effect to be expected is sedation, which can be reversed using an α₂-adrenergic antagonist (eg, yohimbine, atipamezole).

• Age, breed, sex, or reason for emesis induction did not appear to impact whether xylazine is effective in inducing vomiting in cats.