Humane destruction of horses with a mixture of quinalbarbitone and cinchocaine.

The research examined the effectiveness of a mixture of quinalbarbitone and cinchocaine for euthanizing horses, determining it to be generally successful but noting some instances of muscular activity and gasping.

Research Methodology

• A total of 102 horses that needed to be euthanized for various reasons were the subject of this study.
• The researchers used an intravenous injection of a mixture of quinalbarbitone sodium and cinchocaine hydrochloride. The dose rates applied were between 1ml per 10 to 30 kilograms of horse bodyweight.
• The time of injection varied from 5 to 25 seconds, and the reactions of the horses and the time taken for them to collapse and die were recorded.

Findings

• On average, horses collapsed within 34 seconds from the start of the injection and reached clinical death in 230 seconds.
• Prolonged injection times, especially with lower doses, resulted in a longer time to collapse.
• When horses were premedicated with detomidine, a sedative, the time to collapse was also extended.
• Horses that were premedicated with xylazine, another sedative, and given lower doses of the euthanizing mixture exhibited unacceptable levels of muscle activity and gasping. Death was also delayed under these conditions.
• Premedication with romifidine and butorphanol resulted in a slight decrease in collapse and death times but this was insignificant. This combination also resulted in significant agonal gasping.

Conclusion

• Without premedication, the mixture of quinalbarbitone and cinchocaine proved effective. It caused a smooth and quiet collapse with the cessation of cardiac and respiratory functions within three minutes in all cases.
• As a caveat, the palpebral reflex in the horses was notably extended beyond the time when all other reflex activity was lost.
• Lower dose rates and either very slow or very fast rates of injection led to occasional gasping and muscular tremors, particularly in the upper forelimbs.
• Unacceptable violent muscular activity was observed in one horse that was premedicated with xylazine and given a very low dose at a slow rate.