Banning

Banning is a character in Skyrim. He can be found in Markarth Stables selling war-dogs. If you ask, he will say his family has been training war-dogs for many years. A dog can be bought from him for 500 gold.

He is a cannibal for he is present at the feast during The Taste of Death quest, where he states he feeds his dogs on human flesh......

Bugs
If Vigilance is killed, Banning will not offer to sell another dog to you. Any attempt to resurrect Vigilance with a cheat code will resurrect the dog in the Neutral team and not as your companion. This means that Vigilance will return to Banning's side; however, he still will not offer to sell him back to you. (Confirmed on PC: Unpatched, and the problem may exist on other versions.)

No solution has been found as of yet to regain Vigilance once he has died.