Assessment of xylazine for euthanasia of anoles (Anolis carolinensis and Anolis distichus)

Intracoelomic (IC) injection of xylazine was evaluated as a chemical euthanasia method for Anolis lizards (Anolis carolinensis or Anolis distichus). Lizards were allocated into 5 groups of 10 animals each. Each group was euthanized by one of these methods: 10 mg xylazine (100 mg/mL) IC; 10 mg xylazine and 0.5 mg acepromazine (10 mg/mL) IC; 10 mg xylazine IC followed by intracardiac injection of 0.1 mEq KCl (2 mEq/mL) once heart beats were no longer discernable by Doppler; 500 mg/kg 1% NaCO(3)-buffered MS222 solution IC followed by IC injection of 0.1 mL unbuffered 50% (v/v) MS222 solution (experimental groups); and 1.95 mg sodium pentobarbital, diluted 1:10 in sterile water (38.9 mg/mL) given IC (control group). Compared with those given sodium pentobarbital or MS222, lizards euthanized by using xylazine showed prolonged persistence of purposeful movement after cardiac arrest. Therefore, xylazine is not an acceptable alternative euthanasia agent for use in anoles.