Personalized Happy Birthday with Dog and Mouse Women's Plus Size T-Shirt. Dog and Mouse are excited to wish you the happiest of birthdays! Happy Birthday with Dog and Mouse Women's Plus Size T-Shirt - White, perfect for those who love this friendly duo from "Dog and Mouse" by Michelle Nelson-Schmidt. 100% combed ringspun cotton premium jersey (CVC Colors are 60/40 combed ringspun cotton/polyester)