There are innumerable dog breeds in the world, each with a different size, characteristics, other physical features and behavior or habits. Dogs have also been selectively bred and this has resulted in many more species or breeds. Selective breeding of dogs leads to hybrids which can vary greatly in size and features from the parent dogs.
Thus many variations in different breeds of dogs tend to occur. Some dog breeds in the world are much larger than the others. For example, Saint Bernard is considered the largest dog breed in the world. This breed has a height of 70-90 cm and weighs about 60-120 kgs.
The English mastiff breed of dogs is yet another breed which is one of the largest and the male has a height of about 75 cm. They can weigh upto 110 kg. The Neapolitan mastiff is also counted as one of the larger breeds as it is about 79 cm tall.
With a height of 74 cm, the Newfoundland breed of dogs comes on the list of the largest dog breeds in the world followed by Dogue de Bordeaux which has a maximum height of 67 cm. some other large dog breeds include Great Dane, Irish wolfhound, and Kuvasz.