Baby Guinea pig being too dominant with older Guinea pig

[pigmommaproud]

About a week and a half ago, one of my beloved piggies passed away. I had 2 at the time and suddenly I then only had one. I spent the day cuddling with my baby and thought that he needed a new sibling. After doing much research and talking to a vet, I came to the decision to find him a little brother. So I went to the pet store and found a piggy that, I figured, would be a perfect match. I left the new little guy alone in his new habitat for 2 days. After having some time alone, I slowly started to introduce them. First, on my chest which they did fine with. Then a day later, in a play pen covered with towels (did this for a couple of days), which they also did fine with. And lastly, attempted the transition into a cage. But I’ve found that my new piggy tries to assert his dominance, almost constantly, while in the cage. He attempts to hump the older pig frequently, chases him, steals his toy and sometimes food. I’ve tried to find information on baby Guinea pigs (8 or 9 weeks) asserting dominance on older Guinea pigs (2 and 1/2 years old).. but have found literally nothing. I am afraid that this new addition to the family is causing way to much stress to my older piggy and that’s the last thing I want. I am unsure of what to do at this point, other than to just let them be on their own.

 

[Piggies&buns]

I’m sorry for your loss.

I'm afraid you have not carried out the bonding correctly. As you have introduced and separated them multiple times, then you have interrupted everything and they have not been allowed to form any acceptance or the start of any relationship. Bonding is a one time thing all done on one day and seen to conclusion (which is permanently moving in together if acceptance occurs). Any separation after the very first moment they are put together stops the process and means they need to start again. This is stressful for them and can, in some cases, hamper the bonding process.
A meeting of several hours in a neutral territory with no hides (only a pile of hay) is needed. If all goes well, then you move them to the thoroughly cleaned out and also neutral cage and never separate again. It then takes two weeks of permamently being together for a relationship to fully form

You say transitioned to a cage - did you clean the cage down first? Have you put them into the younger piggy’s cage? I’m wondering this because he may be seeing it as a territory invasion if it wasn’t cleaned down and rearranged first

Please follow this guide on how to carry out a bonding
Bonding and Interaction: Illustrated social behaviours and bonding dynamics

Now you have put them together and left them together, they are only just starting the process. Please make sure they are on neutral territory for several hours - not in the cage of either piggy - and leave them together for several with no hides. You are going to see humping and dominance - it’s normal. Stealing food is also normal.
While they are in the bonding pen, clean out the cage they are to live in and after several hours in the bonding pen, move them to the cage.
Ensure the cage they are to live in is big enough for two boars - that is a recommended 180x60cm but 150x60cm as a minimum and that all hides you do use in the cage have two exits, along with multiple of every item (two bottles, at least two hides, two hay piles etc)

However, as this is a pet shop piggy and an on spec bonding, I’m afraid there is never any guarantee of a successful bond. Two piggies need character compatibility and if they don’t have it, then they will not be able to live together

A Comprehensive Guide to Guinea Pig Boars
Boars: Teenage, Bullying, Fighting, Fall-outs And What Next?
Dominance Behaviours In Guinea Pigs

 

[Piggies&buns]

To add, fear aggression can also occur when a piggy is feeling insecure and they can become overly dominant as a way of compensating for their fear.

Moody Guinea Pigs: Depression, Bullying, Aggression, Stress, Fear and Antisocial Behaviour

 

[Freela]

Bonding for guinea pigs is a one-time event, not something that can be done over a series of meetings and separations. When you separate them, they have to begin the process over again. So your boys are at the beginning of the process if they haven't had time to establish their relationship. In the beginning, they need to establish a hierarchy- one will be dominant pig, one will be subordinate, and they have to both understand their roles. There's nothing that says the older pig will be the dominant pig, it's very much down to personality and not age (I've had a new baby move and become the boss. It happens!) Chasing, humping, rumbling, etc. are all normal dominance behaviors as pigs establish where they stand with each other, so don't panic that this is a failed bonding. Have a read of some of the stickies at the top of the page that detail normal bonding/hierarchical behaviors so you know what's normal and what's an issue, then let them work it out and only intervene if there are actual signs of aggression rather than normal dominance. Hope this helps a bit and hope your boys settle in together!