Personalized Dog and Mouse Best Friends Youth Long Sleeve T-Shirt. Friends are always there for you - rain or shine. Dog and Mouse Best Friends Youth Long Sleeve T-Shirt - Heather features two scenes of this budding friendship from "Dog and Mouse" by Michelle Nelson-Schmidt. youth long sleeve t-shirt. Shoulder-to-shoulder taping. Youth: S(6/8), M(10/12), L(14/16), XL(18/20)