I would take your puppy back to that groomer ! It is wrong to sedate a little pup
Allow your pup to see the brush before even using it on him. Be gentle brushing him. He may have been traumatised going to the groomers. Use reward treats. He has to get use to all people in the home brushing him, not just one person.
He needs to accept the brush and understand that he is not boss of the brush. Make it a fun, pleasant experience. Talk to him when you brush him. Use the conditioning spray as well.
