But only when I talk to my dog. He likes the way it sounds and he cocks his head intently. The thing is, I have heard other dog owners say it the same way!
I’m told to believe it’s a southern Thang.
I can make two syllables in two letter words. Easy with a drawl.
I may even say wol-lef for wolf. If that’s what you mean.
I think Bela Lugosi as Dracula in the 1931 film pronounces it somewhat like that. 
Says a wol-lef-pup. 
On the reality show Gold Rush, the kids in the entitled family called them “woofs”. God they were annoying.
Wasn’t there a cartoon show where sheep ran around yelling “It’s The Wol-ef!”
Mike Wolf of American Pickers pronounces his name ‘Woof’. It was indeed annoying.
Oh… I’ve never heard anyone say ‘wol-ef’, but I’ve heard Canadians and Irish pronounce ‘film’ as ‘fill-um’. (And of course plenty of people put an extra ‘a’ in the of ‘rigmarole’.)
Is it related to when some say fil-’em for film?
See above.
ETA: Forgot to delete ‘the of’ in the last sentence; but I’m leaving it so that you know I didn’t edit. )
So noted 
Inserting a vowel to make consonant clusters easier to pronounce (the technical term is epenthetic vowel) is fairly common in English and other languages. See fil-em above, or ath-a-lete, or mil-uk.
I’ve never heard it with wolf, but it wouldn’t surprise me if I did.