Neutering is such a common surgical procedure in all veterinary practices. I was surprised that the other veterinary clinic did not want to neuter this gentle Golden Retriever as the vet rejected large breeds.
One cause of the other vet's reluctance could be the complications of neutering. One complication would be post-surgical scrotal haematoma due to haemorrhage as the dog licked and traumatised the wound. Over 48 hours, the scrotum became swollen to as big as a tennis ball in big breeds. Such cases are rare but had happened to me too.
What's the prevention advice. Basically, double ligation and sufficient post-operation pain-killers. One such case with no post-op problem is shown here, in 3 images.