What is this white powdery substance that gets on my hands after petting my dog?

I have an Akita (kinda like a husky) and have noticed when / after she sheds when i pet her a white powdery substance gets on my fingers / hands. Please dont say its some kind of disease or take her to the vet, this has been happening for 5 years since ive had her and theres nothing wrong with her shes been to the vet plenty of times, im just curious? Its not flaky or anything like dandriff or anything like that and i repeat there is no illness or ANY problems with her, this isnt the first or last time i will notice this