Which breed of dog is the largest by weight?

A Rothweiller or a Saint Bernard i would think..

That depend weather you have a small dog thats fat, or a big dog thats skinny

The largest recorded dog in the world was 480lbs. It was an English Mastiff. Mastiffs are the heaviest dog, but not the tallest. The tallest is the Irish Wolfhound. The tallest Wolfhound was a recorded 5 foot high at its shoulders. Hope this helps.

thats a very good question!!

I think a great dane.

I have a very large, now 8 yr. old neo mastiff, who in his prime was 225 lbs. Now he is down to 185, and looks tiny to me!! Mastiffs, St. Bernards, Caine Corso, Great Ganes. there are a lot!

The St. Bernard Dog is a large breed of dog originally bred for rescue and as a working dog. A full-grown male can weigh between 150 and 220 lb (68 and 100 kg). There are two varieties of the breed: the short-haired or smooth-coat variety and the long-haired or rough-coat variety.The Saint Bernard is known for its loyalty and vigilance and is tolerant of both children and animals. Because of these traits, it has become a family dog. They also make good watchdogs, as their size can be intimidating to strangers, though their temperament is gentle. English Mastiff is also another heavy breed of dog. -