Every breeder I've personally talked to for a puppy usually requires a neuter around the 18 month mark in their contract (although I haven't talked to my current one about this). I admit this is maybe easier to get around than I thought- since I didn't end up buying a puppy from them, I never asked if they'd allow keeping the dog intact. The reason is this study from last year When Should You Neuter Your Dog to Avoid Health Risks?, an extensive decade-long study of thousands of dogs. It suggests, among other things, that keeping a female golden intact drastically reduces the chances of many cancers (with high statistical significance). Now, I understand there are lots of factors, and also that correlation is not causation. But regardless, is this a choice breeders would let owners make?