
I've had a Rottie and boy can they shed....however,I've not had the bald spots....so this makes me think it could be worth a vet visit.
Re major shedding.........This happened to my dog (st poo) just a couple of months ago....she was losing a lot of coat ,which is unusual for my breed and then I noticed bald patches on her front and at the elbows....we tested her blood for thyroid levels and she was really hypothyroid.....she has been prescribed euthyrin, and a month later I am already seeing new hair re growing. She is also more lively,she was becoming very lethargic too.
Low thyroid also shows itself in even loss of hair on the sides ,flanks, of the dog...hope this helps.