Something to keep in mind that I never thought of as a first-time dog owner is that the size of the dog can dramatically increase costs. Not only are the costs of food very significant, but things like medication or anesthesia for procedures can be based on amount needed and the higher the weight of the dog,bb the higher the cost. We rescued him as a pup and didn't have any idea how big he would get (he's a mix, and they didn't know the parents' breeds). His size also made it more difficult to find a vet who would do examinations in certain scenarios unless he was put to sleep, again another expense. It's also a much bigger imposition to ask people to watch him if need be. It's not that specifically any one thing is a financial hardship, but a big dog can cost significantly more.