Golden retrievers were a breed that was developed to be used. In their native environment int he UK, they would be expected to run through thorny cover, up and down steep banks, dive into frigid lochs and rivers, and leap walls and fences to recover quarry.
And yes, they would be used on rabbits and hares as well as partridges, grouse, pheasants, and wildfowl.
This breed has, unfortunately, become a victim of fashion.
It’s very sad that I think many people would have trouble identifying the British rabbit retriever in the above photo as a golden. It must be a saluki!
Stunning dog, looks just like the Golden I grew up with. We still have some like this here in the UK, but you normally only see them within the working gundog community