Looks like a pit hybrid purely bred for size.
No it doesn't. It looks like a male pit thats in good shape. My female carried that degree of muscularity---she was smaller obviously, when she was younger (she's almost 11 now and age, combined with a torn up knee is starting to show her age). When I was in veterinary school, she used to drive me crazy wanting to play all the time. So we compromised, I built a "dog powered" treadmill that she'd jump on and do windsprints while I sat in front of her in the chair trying to study holding a rawhide bone. She literally ran until she wsa too tired to run every night.
I'm willing to bet the owners did "conditioning work" with that dog--either on a treadmill or with sled pulling of some sort.
