How does weight gain affect a bullmastiff?

Asking because it's a heavy breed prone to HD (correct?)

Can't really go into details but know one that is hugely overweight and didn't know what problems exactly it would present for a BM?

Thanks

HD is not the only danger to large dogs. All joints will strain under too much weight, and especially the heart will be working on overtime.

Thanks DP, there are certain things I already knew but wasn't sure if there was anything directly relating to the breed, I recently met the BM in question and her face is very squashed - will the extra weight have an effect on the respiratory system as well?

TBH I don't know for a fact, but I can imagine, like with any overweight person or dog, the whole system will be working much harder than it should.
Could you perhaps ring a vet in the morning? That way you could also provide the dogs owner with "facts from a vet" whic h may weigh heavier (excuse the pun ) than something someone told you over the internet.

They could suffer from reduced breathing capability, yes.