well i have a sheltie too and i use doggy shampoo on her but human conditioner. it hasn't done anything to her yet. oh and i also use it on my shi tuz too.

yes, but try some thing mild like baby shampoo, that way your dogs skin will not get damaged by the other shampoo.

Yes, it's fine to use either one will be fine. Just make sure you rinse her off well. I have a Sheltie and use human grade shampoo & conditioner on her. I show her in breed and she has a beautiful coat & healthy skin! Just be careful of her eyes as well. All the best;^)