I have a 13 month old male and in a few weeks I will be getting my first little girl, but I am not sure which one I should have neutered.  The boy has a brilliant personality and I do not want to change that.
But at the same time I really do not want any accidents with the girl getting pregnant (I am not a breeder and will leave that up to the experts!!!!).  I just hate the though of putting one of them through the pain of an operation!!!!

Please can you give me some advise!!! 

Would arrange to kennel one or the other when the bitch has her first and if possible her second season and then have the bitch spayed. The reason I say have the bitch done is that in my experience the bitches seem to tolerate the removal of the gonads better than do the dogs. The bitch may become a bit more bossy after the op but the bitches are normally the boss anyway so it will keep things more as they should be, sometimes castrated males become some what defensive.

I have 3 entire males and 1 bitch. I have had the bitch speyed and there are no problems either with the bitch or the males....I would do it this way again.
Archer

That is a carbon copy of my situation Archer, but my bitch was not spayed till she was 4 and only then because of a problem whelping. But she is still boss and rules with teeth of iron and all the gents do as they are told.

Yep my Zara rules the roost...and shes a quater the size of the boys!!woman power!!
Nikki