I have 2 males that are not neutered and yes, they do fight. I have to keep them separated. (They are my show Silky terriers.) But I also have 2 females in the house who are spayed, but that does not seem to help the situation.
One of mine is 4 and the other is 15 months....we brought in the 4 year old last November.....and for 6 weeks everything was fine.....but then we think someone in the neighboorhood came into heat....because they got into to it regularly until we separated them at all times.
From what my breeder told me.....the older unneutered dog will be patient with a new puppy........but mostly like the problems will arise when the puppy grows up and the puppy begins to challenge the older puppy.....and that is exactly what we saw happen.
Sorry, I have no experience with unneutered males.....but my spayed females do get into it at times - but that may be once every few months....not daily/weekly.
Good luck.....and Yes I think dogs like a companion in the house....at least it seemed to help alot for us with the separation issues when we leave for work!
__________________ Kristin, Mom to: Lil Mis Magic, Sailor and Captain |