I think the six months for boys is most common. Our vet says between 7 to 9 months for toy dogs --- partly to do with weight and partly to wait on status of teeth, since they usually need to have some baby teeth pulled.
I don't think think there would be a problem with doing the surgery earlier, but I would depend on your vet's advice.
If I remember correctly (sure more knowledgable folks here can correct) the breeders I talked to who insisted puppies be altered before sale kept them until 5 months. |