I can understand them not wanting you there during grooming. Mine get too excited and fussy when they see me. But it may be different with an experienced show dog.
However, not knowing how to leave 4 or 5 inches of hair shows inexperience. I'd look for another groomer.
__________________ Mike ~ Doting Dad to Jillie, Harper, Molly, Cooper, Eddie (RIP), Lucy (RIP), Rusty (RIP) and Jack (RIP). Check us out on YouTube |