Commentary for Avodah Zarah 31:14

“Struggling” refers to an animal that was dying before it was slaughtered. If after it was slaughtered it “struggles” then we can assume that it was alive and the animal may be eaten. R. Hanin here is discussing the status of large wild animals. All agree that their status vis a vis struggling is the same as that of a small beast. But when it comes to selling them to non-Jews, there is a dispute. The first opinion holds that large wild animal may never be sold. In contrast, R. Hanin holds that like small beasts, it depends on the custom.