Why doesn't this hat fit wendy!!!

This morning I went out-side to see my dog(wendy). I went out there and took a dog hat that my friend gave me. So, we tried and tried to get that hat on, and then we realized that her head was to big. I was holding it in my hand then Wendy licked it. Then, we tried much more so our conclution was the hat doesn't fit!!! Any idaes, please coment?