[Ellie May]

I don't think tartar build-up would cause bleeding.
Inflammation/gum disease could though.

If the gums/teeth are so bad that they are bleeding when brushing, maybe Mocha needs a dental?

I really don't know but Ellie had stage 3-4 periodontal disease and after oral surgery now she has stage 1. I didn't brush before, so I don't know if she bled but while brushing now, she doesn't. I even floss her teeth and have seen no blood. Maybe call the vet and talk to them about it?