No pitbull shouldn't be mixed with another breed.
As I know, there is no rat face bloodline. Rumors include a rat terrier cross breed. I dont recomed cross breding a pitbull with no other dog breed.
I can recommend you to breed a pitbull and another pitbull. You see? Pitbulls have a estable behaviour and mixing with another would not make a better breed.
American pitbull terrier
The breed is The American Pit Bull Terrier. Some people shorten the breed's name but it is the same thing.
A rat terrier is the breed. Smooth is the coat - Flat/ short. You can also get Wire. Its the same dog...
amstaff terrier and pitbull
There is only one pitbull breed. The names you hear are the bloodlines names within the breed. Dogo would refer to some bull breed names which the pitbull isn't related.
She will clearly show you when she is ready and in heat.
very vistios the pitbull i s vitios
pit
It is a mix breed of Pug and Rat Terrier I have one and she is the sweetes thing!They have also proven to have less health problems then a puggle.