male guinea pig aggression

Question
I had one male guinea pig for 2 months then got another male guinea pig (both are 4-6 months old now) and at first there was some dominance issues, but then they got along and played together.  Now, about a month after having them both together, the older and larger one is constantly mounting the smaller one, biting him, nudging him and it has gotten to the point the smaller one sits in his house all day (when the larger one doesn't run him out) and will not play or move around at all.  Even in their playpen the small one won't even walk around anymore.  He is still drinking some water and eating some food but seems very stressed and depressed.  I have heard getting the more aggressive one neutered will not change his behavior, but I also don't want to separate them unless absolutely necessary.  How long can this aggression go on before I should separate them for good? And what should I do if the smaller one is depressed?  Thank you

Answer
Hi Lauren,

This seems like a rather odd situation! Usually the mounting/biting/nudging/circling behaviour occurs when two unrelated guinea pigs meet each other for the first time, to establish who is the dominant male. As long as the larger one isn't hurting the smaller one, I wouldn't split them up. Guinea pigs only thrive when they have a cagemate, and the older boars get, the more difficult it is to find them a new friend.

Try making a hidey-hole that only the smaller one can fit in; this way he can hide when things get too rough, but mix with the larger piggy the rest of the time. Make sure the small one is getting the food and water he needs, and get him out for extra cuddles.

If he seems really withdrawn or the fighting turns harmful, you will have to separate them permenantly.

Good luck!

Jenny.