I bought this set unsure of what size I would need for my family's mid-sized dog. I would have to say that the three sizes of cutters are probably about the right size for small, medium, and large dogs. That said, I made both medium and large cookies for our dog. For very large dogs, I would wonder if the largest cutter of this set is big enough. As for the construction, the seams are very obvious and I could see them being the failing point - hopefully not for many years! That said, I'm very pleased with this set and I'll definitely be using it a lot!