With the choices you gave, it would be the 9mm. I am not sure I would go after the model 9mm you wanted as I believe there are better choices out there. But my reasons for picking the 9mm over the .357 are;
ammo is cheaper, so you can practice more.
recoil a much less so a quick second shot is usually more in target.
9mm usually has a much larger cartridge capacity in the case of wild dogs, multiple shots might be needed.
with the correct ammo, a 9mm is still a very deadly cartridge. Especially for canines or hogs. You want to hit center mass, and let the bullet do the work.
I just feel that a pistol is often more easy to aim and shoot in a high stress situation. also they are faster to reload.