the dog will eat more than a normal dog. i had a neighbor that asked me for money to feed his dogs and i hated that because i dont have a dog for that reason
The Spanish used giant dogs, similar to the Canary Islands Presa, to attack the Indians when they invaded the Americas.
The reason huge dogs are not popular is that you pretty much need to kill a cow a week to feed them.
The Canary Islands were named for the large dogs (Cane) and then the much less noticeable tweety birds were named for the Islands.
The Romans visited the Canaries, but did not get around to conquering them. The Spaniards made the Canarios their first colony. Many of the locals did not like being conquered and were rebellious. The Spanish rounded up many of them and resettled them around Montecristi. Later the Spanish punished the people of Puerto Plata and Montecristi for doing business with the English and the Dutch, and depopulated both towns and resettled the people in Monte Plata
Many of these people returned when the Spanish installed a new governor.
On the other hand if you have a huge dog hanging around your property, it is very likely no one will bother trying to rob you.
Then the issue becomes whether feeding the huge dog costs more than an occasional theft.
I saw a Neapolitan Mastiff in Uruguay that must have weighed 190 lobs. It was a very old dog, but it was truly scary.
It looked like a Great Dane on steroids and had a very impressive growl, more like a grizzly bear than a canine.