I don't think I've ever used a ladder stitch before. Learn new things every day :) A fantastic tutorial for how to sew openings closed by hand using a ladder stitch. Pictures to guide you through every step!
How to Make Felt Baby Shoes – Step by Step-These would be so adorable made with handmade felt, and embroidery. Maybe could use the same pattern for puppy shoes. Would try to strengthen the bottom of the shoe so they won't have pickers poke through.