A referendum on animal protection was held in Switzerland on 20 August 1893. Voters were asked whether they approved of prohibiting butchering without the animals being anaesthetised. The proposal was approved by 60.1% of voters and a narrow majority of cantons.
Swiss animal protection referendum, 1893 Wikipedia
The referendum was a popular initiative, forced by the collection of 100,000 signatures. As it involved changing the constitution, a double majority of both votes and cantons was required for the proposal to pass.