17.1. American Kennel Club
At http://images.akc.org/pdf/breeds/standards/AmericanStaffordshireTerrier.pdf, the AKC in their breed standards state,
Head: Medium length, deep through, broad skull, very pronounced cheek muscles, distinct stop; and ears are set high.
Muzzle– Medium length, rounded on upper side to fall away abruptly below eyes. Jaws well defined. Underjaw to be strong and have biting power. Lips close and even, no looseness. Upper teeth to meet tightly outside lower teeth in front. Nose definitely black.
Size: Height and weight should be in proportion. A height of about 18 to 19 inches at shoulders for the male and 17 to 18 inches for the female is to be considered preferable.
Approved June 10, 1936
