Can one give a male rabbit to a non -Jew and ask them to give it to the vet to neuter while it is in their possession, and then return it afterwards to you?
The gentile is also not allowed to neuter the rabbit, as gentile are also not allowed to castrate animals. Therefore by giving to him you are causing the gentile to sin, which is lifnei iver. Hashem made the world in order for all species to be able to procreate, and He doesn’t want Jews nor non-Jews inhibiting this.
Shulchan Aruch Even Haezer 5-14.