Red nose pit bulls and blue nose pit bulls are characterized by the color of their nose leather. They have similar body types and skin colors.
The red nose pit bull breed came to the United States from Ireland in the 1800s. The red coloration of the nose leather was an unintended side effect of breeding the dogs to be more aggressive. The history of the blue nose pit bull is not known. Some breeding experts state that the blue nose breed was a term given to pit bulls without the red nose in order to make the standard pit bull breed appear to be a special breed.