I am glad your dog did not swallow the hook.
Unless it is a stainless steel hook, the acids in the dogs digestive system will tak care of it.
It is not a particularly uncommon experience down here. I can think of at least six dogs that have swallowed hooks, none died, got sick, etc and none had surgury. My cousins dog at a bait with hook on my boat. You could see the hook in the xray. A few weeks later, no hook in the xray. Fish swallow hooks all the time and survive. I am not saying it is a good practice, let your dog be exposed to a baited hook. But chances are the dog would be fine. Also chances are if you went to an old country vet, he would just watch it and a younger urban vet would be cutting on your dog.
Personally, I would be FAR more worried about a dog swallowing monofiliament line than a hook.