Male Guinea pigs fighting for dominance

Question
Dear Andy,

We have a couple of male guinea pigs which are about 8 months old, both from the same litter.
They have lived more or less harmoniously for the past 8 months in the same hutch. One (Bubble) is quite a lot bigger than the other (Squeak) although the smaller seems to have been catching up of late.

I have recently built them a new pen for outdoors and they have been using this harmoniosly and enjoying grazing on the grass. However, today when we put them into the pen the smaller has been intent on mounting the larger one and, shall we say, attempting to 'have his way' with him.

This has rather angered Bubble and a furious battle for dominance now seems to be going on. After scurrrying around for a while trying to mount each other they separate, teeth chatter and lunge towards each other. Normally shy of us, they don't seem to care if we get in the pen or shout at them or anything but carry on imperviously. We have had to separate them as we feel they will harm each other if we don't. Even separated the smaller one sniffs the air and is intent on trying to reach his brother.

I've tried putting them together again but the same thing happened and I quickly had to separate them.

We are not quite sure what has brought on this change of behaviour, other than the weather over the last week has been very hot and dry and my daughter changed the position of their hutch within the shed yesterday.

Any ideas what we should do? Should we leave them to sort it out? Should we have them neutered? Should we separate them for a time and then try them together again?

We'd be very grateful of any help you can give us.

Thanks

Mike Bell


Answer
Hi Mike

My guess would be the change to their hutch position / conditions would be the most likely reason for the behaviour. It sounds as if they are establishing dominance in "their" territory.

Sadly, it sounds from what you tell me that they have got to the stage where they might hurt each other if left, so you have done the right thing in separating them. Common thought seems to be that neutering will probably have little effect in most cases so it might be somewhat of a waste of time going down this route.

Sadly, some pigs just have their disagreements. You can leave them together to sort out their differences providing you are confident they wont actually inflict injury on each other.

Good luck

Andy