personally, id carve just the generic outline of it, i wouldnt try and do the wrinkles with the cake. for the face, id use sugarpaste (fondant ) sausages, to get the shape and definition of the wrinkles, and then id cover it totally with a piece of rolled out fondant and smooth it to the wrinkle shape , if that makes sense . . .
If it were me I'd probably use a RKT head...then use LOTS of buttercream on it to shape the face. Then put it in the fridge to chill up real well...then cover in the fondant. When you put the fondant on, you can pinch and wrinkle the fondant, and with all the buttercream underneath, you can form the fondant into wrinkles, indent the eye sockets, and made the mouth and stuff fairly easily. I have several 3D dog cakes in my photos if you want to take a look...did a pug too, but lying down...
This link to pink cake box making a bulldog may help with the face and wrinkles.
see this tutorial for doing the face:
Thanks to all of you!
I like the idea of the RKT head, I was nervous about how stable cake would be for that.
Would you think it best to start with maybe 3 oval layers for the body and carve it?
He only needs about 25 servings, I always get nervous about servings when I carve.
Then since it won't be too big maybe I can just make the legs out of fondant?
I'm off to check out those links now.