The Italian Mastweiler is a combination of the Italian Mastiff (also called the Cane Corso) and the Rottweiler. Since both of these dogs are large, your Italian Mastweiler will also be large and should be about 75 to 120 pounds when fully grown. They enjoy working just as much as playing and prefer to be busy at all times. Although the Italian Mastweiler is a loyal and loving pet, they are also excellent guard dogs because of their strength, size, and courage. They do need early socialization and thorough training because they are very strong and can be a lethal force to contend with in the wrong hands.