What is used in euthanasia for our pets? I looked on line and found this:
“For large animals, the volumes of barbiturates required are considered by some to be impractical, although this is standard practice in the United States.[5] For horses and cattle, other drugs may be available. Some specially formulated combination products are available, such as Somulose (Secobarbital/Cinchocaine) and Tributame (Embutramide/Chloroquine/Lidocaine), which cause deep unconsciousness and cardiac arrest independently with a lower volume of injection, thus making the process faster, safer, and more effective.”
So, this would explain why we use a cocktail of drugs instead of straight pentobarbital or sodium thiopental.
It also notes that:
“Occasionally, a horse injected with these mixtures may display apparent seizure activity before death. This may be due to premature cardiac arrest. However, if normal precautions (e.g., sedation with detomidine) are taken, this is rarely a problem.[6] Anecdotal reports that long term use of phenylbutazone increase the risk of this reaction are unverified.”
Which would help explain why we sedate before execution. We don’t want to see them uncomfortable as they die, it makes us uncomfortable too.