I attempted this concept a few years ago in cross stitching but it was so tedious that I got barely halfway through before quitting. Felt is so forgiving compared to aida!
I sketched the outline of the dog on tissue paper and then stretched that with the felt on the hoop. I embroidered right through the tissue paper, and then when I was basically finished, I tore the paper away. I’m not sure if this is kosher embroidery, practice but it seems to work!