I've always known he has. The Kirayth use a stylized wolf's-head as part of their logo, and Capri called Fenris "O'd Wuff" as a toddler... and there's the use-name Fenris chose, after all...
...but, though a mutt, he's mostly Bartomn. Which is ursine-ish. L'Arath, Jeramie's House, is the House that's generally associated with wolves.
He does it to piss Jeramie off. The old saying was that L'Arath was the sword of the Lishaya, and Bartomn her shield; taking the wolf imagery for his de facto police force was Fenris's way of saying, essentially, "If you're not going to do your job, I will."
Which, y'know... that's how I'd been taking it. Just, "you're not doing your job." But I was writing at lunch today and hey, there's the reason! It was just back about 20, 25 years.
'k. Back to work.
My brain isn't nearly as frayed today; let's hope it stays that way! Still way frayed. Just not at panic-attack level.