I’ve grown up with a handful of labs. All have had a share in eating dead animals and never seem to get too sick. Usually just throw up whatever they ate if it’s too bad. Could tie the “dead animal” to their collar for a week or so. That might change the dogs habit.
Guys ecollars are easy correction. They can be abused but so can a stick or someone’s hand. I don’t condone hitting a dog but a nick is no different than burning yourself on a hot pot, you’ll be careful next time, you had a negative experience