The Safety Profile of the Anesthetic Effect of Alfaxalone and its Interaction with Xylazine and Ketamine in Chick’s Model (Gallus Gallus Domesticus)

The objective of our research was to estimate the therapeutic index and assess the interaction of alfaxalone (IP) with ketamine or xylazine (IM) in chicks by using isobolographic analysis. The up-and-down technique was involved to calculate the median effective anesthetic dosages (ED₅₀) of alfaxalone, xylazine, and ketamine given separately or at the same time in young chicks. Then the up-and-down technique was involved to estimate the median lethal dosage (LD₅₀) of alfaxalone (IP) to determine the safety profile. The ED₅₀ of all anesthetics was evaluated isobolographically to assess the type of interaction between alfaxalone and xylazine or alfaxalone and ketamine. The alfaxalone ED₅₀ was 32.88 mg/kg (IP), whereas the LD50 was 102.40 mg/kg (IP). The ED₅₀ values for alfaxalone, ketamine, and xylazine were 32.88, 12.24, and 2.45 mg/kg, respectively. The ED₅₀ values of alfaxalone with ketamine or xylazine (25:25 ED₅₀ values) were: 7.39+2.35, and 8.61+0.63 mg/kg, respectively. ED₅₀ values were decreased when the combinations of alfaxalone/ketamine or alfaxalone/xylazine were administered by 22-21% and 26-25%, respectively. The anesthesia of chicks with alfaxalone is safe, produces a surgical stage of anesthesia, and can be used for minor surgical procedures. The use of alfaxalone with ketamine or xylazine has been shown to have a synergistic effect and these findings may be of clinical relevance in poultry or may be extended to mammals following further clinical trials.