With late XXI century tech, wildlife replication is becoming commonplace. Dodos? Small dinosaurs are piece of cake. Dinosaurs? Large birds are big to deal with, but doable. So long you get a viable DNA sample, any animal can be replicated.
They need to be grown from infant stages (no insta-t-rex machine) and function as a normal born animal after that (by the way, some asian country now has a eternal dynasty of clones of their supreme leader, but that is for another day). They need to be tamed, trained, reared, shoed, etc.
Hunting and safari now are commonplace, because if you have enough biomass and energy, you can just keep making more animals. And of course the world is having tons of protests from animal rights defenders, but this is yet another tangent.
So Mr. McHound wants to get his killer hounds to fight all the animals there are. Is there any animal these dogs can't kill?
- Land animals only. Of course the dogs will have no chance of killing an angler fish that never comes above 3,000 feet under the sea.
- Only animals weighing more than 1lb. Don't go saying the dog can't chew tardigrades.
- Hard Science question. Please take this in mind.
- Any animal that ever lived on Earth with the requirements above is fine.
- No genetically modifed animals. All the animals in the safari are standard versions of the ones that live(lived) on Earth.
Regarding the dogs:
- The dogs are of a breed made for war created from several ferocious XX century breeds. They are not transgenic, but can be considered the pinnacle of canine crosbreeding.
- Dogs can be cloned, and even though they have to be trained, if one dog of the pack survives, that is fine.
- The dogs are trained for combat / killing / war.
- Pack size is anything greater than 5 dogs.