here is a product that our dermatologist recommended and it did help Duke's hair grow back. there is a ton of information to read about it..
Nu-Stock - Topical treatment for Horses, Dogs, and Cattle
we believe this and a combination of healthy diet really helped! your bulldog is beautiful!
Ive heard of and seen good results with melatonin. We have a bully in rescue with it and his hair is growing back in.