[guerrilla]

They do actually, for example with swine in Denmark. They've built fences for that purpose specifically.

[mnky9800n]

Do they have passports? Like how do they know if the pig is danish or German?

[guerrilla]

I think many are tagged, but otherwise they have a lot of surveillance and fences. They probably track them after breeches as well. The point is to control disease.