Jaguars have been trained to dislike the taste of cattle, sheep and dogs by feeding them tainted meat, suggesting a way to spare the lives of both domestic animals and the predators that prey on them.

An endangered species, jaguars roam freely under wildlife protection laws in Mexico and parts of Central and South America. But their attacks on livestock and pets have led to illegal shootings by angry owners.

By treating meat with high doses of deworming medication and wrapping …