I will disagree with either of the two above....not because they are wrong, I would just have another preference.

The 12 gauges will give you a few more yards of range, but you will cause significant damage to the hide of the yotel dog. Not to mention you would not be very precise with the shotguns.

What I would do if I were you is go with the .22 Savage. CCI Highpoint ammunition will cost a couple of dollars more because it is higher velocity ammunition, but you are getting a 29 grain hollow point bullet that has a MV of around 1450 ft/sec. That is enough to have a precision shot that does very little damage to the hide and will be fatal up to 40 meters or a fuzz more on a yotel.

The 12 gauges will be a touch more powerful....but they are messier and MUCH more expensive to shoot.

~Cam

p.s. I hope this helps, and is just my opinion....but for the record I have taken the majority of my yotels with a .22 LR in N. Idaho from 50 meters and closer. I also ear-holed on from 100 yards, mostly luck, but dropped the yote on the spot!