I'd find a vet that uses inhaled anasthesia (gas like Isoflourane). These guys are way to small to be using injectable anasthetics.
I just found this on Xylazine:
*Xylazine: can-0.6-2 mg/kg IM, IV, por-2-4 mg/kg IM, rab, guinea pigs-3-5 mg/kg IM, other rodents-4-8 mg/kg IM, budgies-10 mg/kg IM, bov-0.05-0.3 mg/kg IM, IV, ov, cap-0.01-0.22 mg/kg IV, IV. frog- 10 mg/kg IP, SQ
Alpha 2 adrenergic agonist causing sedation, analgesia and significant hypotension.
May cause 2nd degree heart block and bradycardia in dogs and other species. Frequently causes emesis in dogs. It can be administered to frogs for very effective analgesia of up to 24 hours duration.
I'd find a new vet, if it were my dogs. Sorry
