Even within the same litter, some Corsos will, and some won't have rear dew claws. If they do, they are always removed. The fronts are optional. I like to remove them for three reasons; 1. They're absolutely useless, they no longer serve any function and it just gives you two additional nails to maintain. 2. It's too easy to damage the eye, or eyelid when a dog tries to rub something foreign from his eye (dirt, dust...). 3. The dew claw can be easily ripped from the leg of an adult working dog causing a lot of damage, whereas if removed two days after birth it is a very quick procedure that doesn't even require stitches and never has to be repeated.