What is the name of heaviest breed dog?

The title of "heaviest dog breed" is a little tricky, as it depends on how you define "heaviest".

If you're looking for the breed with the highest average weight:

* English Mastiff: This giant breed typically weighs between 160-230 pounds, making it the heaviest breed on average.

However, if you're considering the heaviest individual dog ever recorded:

* The record goes to an English Mastiff named Zorba, who weighed a staggering 343 pounds!

So, while the English Mastiff is considered the heaviest breed overall, individual dogs of other breeds can sometimes surpass them in weight.