Tips to break dogs from fighting

x2 on neutering the lil guy...it will help out if hes a younger dog but if he is over a few years of age it may not change a thing. i had a female pit that did the same thing to a female cat.... it wasn't just any dog ...just that one female and i ended up selling her to a guy with that cats sister...i explained how she was fighting the cat gyp i had and sold her pretty cheep.he took her and said she never offered to fight another dog....i don't think you have to "cull" him but i would neuter him and let the new owner know he has had it out for your bulldog. some times they do great with other dogs and just hold a grudge for one certain dog. if you decide to neuter him it will take up to two months before he gets all his testosterone build up out of his system. hope this helps! mrs.kbar(dejah)