Essentially, the situation I see potentially evolving in a Libertarian Society…
I believe there would be “pro animal” groups if you want to call them. Organizations like the R.S.P.C.A etc that monitor and get calls about the misuse and treatment of animals.
If people believe there is abuse occurring they could contact the Animal Protection Organization, who then contacts the owners and request an inspection. If refused they could then put a notice out on the person, add them to a online animal abuse suspect list, and keep a database on all others who are known to be abusive. If the owner wishes to remove themselves from the list, they could attempt to prove they are not abusing their animals.
Animal breeders and sellers can check in with this organization before selling to a prospected buyer to make sure the animal won’t be abused.
In the written contract for sale, they could also stipulate they will be allowed access in 6 months time to check on the health of the animal.
In terms of the argument put forward, “what would you do” - if I was present I would try negotiate and buy the dog from the owner who is about to harm it. Bribes would also suffice. Alternatively, if that does not work and he refuses and attempts to harm it.. (burn it to death) I’d use force, steal the dog and accept the consequences.
The consquences being compensation for his property that was stolen. i.e the Dog. This would only happen if the dog owner wants to take you to court. In all likelyhood the organizations / agencies would have clauses / contracts with the individual against animal abuse.
Charities could exist that go around rescuing and buying animals from their owners, putting them into good and better homes. As well as providing the market with easy sources to make sure the abusive owner is never sold another animal again.
I think, kind of outlays like this are much better than the “vulgur libertarianism” of straight up. eg. “Yeah, the animal is his property. He can burn it if he wants.” - It really isn’t the answer anyone wants to hear. And whilst being ‘tough’, I really don’t think that anyone here could stand by and literally not say anything in such a situtation…
But really why is there even a situation like this? The State is the main culprit. Welfarism no doubt plays it’s role and warfarism too. (See: US solider throwing a puppy off a cliff) A lot of problems stem from broken homes, problems in the family. Marriage breakups, stress from taxation, divorce courts, easy money, easy morals, public education… yada yada. So in a Libertarian society, long term - this really wouldn’t be a problem, except very marginally.