Many of my clients have very large dogs. Most of them are under 100 pounds (45kg), but some are quite a bit larger. Dogs like Great Danes, mastiffs, Saint Bernards, and Great Pyrennes are really nice dogs and there is a differen kind of happiness when you have a "giant" breed that you won't find with a toy breed. However, that joy can go away when something goes wrong and there are veterinary bills.
Owners of big dogs know that feeding costs are high because of the sheer volume of food the dogs eat. But prospective owners don't always think about the medical costs. In veterinary medicine we dose based on weight. A 150 pound human is typically going to take the same dosage of antibiotics as a 300 pound human. This is not the case with animals. A 40 pound dog and an 80 pound dog are going to get radically different doses of pretty much everything. This includes antibiotics, pain medications, heartworm preventative, flea preventative, anesthesia, and so on.
Today a client came in with her 120 pound Great Dane. As part of her annual physical we ran a routine urinalysis and discovered an infection that hadn't been obvious to the owner. We talked and it did seem like there were some emerging clinical signs that supported our lab results. The decision was made to put her on antibiotics. The owner was fine with all of this until we added up the costs and the medications alone were nearly $200.
Yes, that's a lot of money! But because of her size and the nature of the infection there weren't a lot of other options. A 15 pound poodle would have taken home the same medciations for less than $30 because it would have a much lower dosage to achieve the same result. I've seen this time and time again, to the point where I actually cringe a little when I order up certain medications for these giant breeds. Unfortunately, I have little control over it, as those higher doses of drugs cost us more to order and stock. The mark-up is the same, but the larger dogs simply need more. Believe me, we're not trying to gouge or penalize owners of these breeds.
When someone is considering getting a pet of a certain breed, I think it's always wise to research the pros and cons of the breed as well as the costs of medical care. When you accept responsibility for caring for a pet you also have to shoulder the costs of that care, which are much greater for bigger dogs. Prepare for the inevitable greater costs, especially if that large pet gets sick.