
Good point, suejaw. We have already had a taste of challenging for top dog. My oldest boy, bless him, is a one ball wonder (hope I am allowed to say this :-)) aged 5 years 3 months --I decided against full castration at the time and had only the retained testicle removed. I never show him and he has always been top dog.
Next up is our permanent lodger, an entire male aged 4 years 10 months. He is not as well socialised as my oldest boy and has been challenging for top dog. He and the oldest boy have scrapped and as a result the oldest boy is kept apart from the two younger boys at all times when they are in confined space (e.g. the house or car) but they run together happily off lead and get on absolutely fine on walks on lead. I occasionally show this dog, as does his breeder, and as he got the reserve at the breed champ show recently he will probably be out in the ring again before long. He isn't mine to decide whether or not to inject and clearly if he is due in the ring this wouldn't be advisable.
The youngest boy is aged 3 years 6 months. He is my main show boy and has started to do pretty well, so I wouldn't consider having him done. He is also very pally with the lodger and eggs him on against the oldest boy.
The arguments started about three months ago and were very occasional, relatively minor events usually triggered by food or who was first in the car. The last one ended in my oldest boy getting a puncture wound, which is why they are strictly separated now. Only the lodger and the youngest boy are allowed out together in the house and for now they are being crated separately just in case.
I haven't wanted to upset the order in the house by injecting the oldest boy, who is really the only one I could have treated. So my compromise is to keep them all at a safe distance from each other at all times, not just during her season.