16 months changes...

just wonderd if anyone had came across the same problem.. beau is now 16 months and the past 3 weeks every dog he has came across just goes for him, no hello, no play, with beau reacting very aggresive.. to be honest I think beau is bringing a lot of it on himself through his body language and whatever else I thought at first it was because phoebe was walking with us so lately I have been taking him out separetly and it is exactly the same..so while up getting his wormer this morn at vets I mentioned it and first words were get him neuterd, I should have known... but there is something goin on and would like to get to the botom of it..

Poor Beau, not too sure what could be wrong as I have never experienced this before, but I'm sure someone will be able to give better advice soon x