First Time Question!

[Michael]

Hi all! First time question and Reddit in general! I thought I knew a good amount of information regarding guinea pigs, but something has happened that I cannot explain. I have 2 guinea pigs, both females. One is about to be 1 years old and is the second one we adopted, and the other one turns one in October. They were introduced in March and have been fine ever since! They got a long like sisters! Two weeks we introduced an igloo into their cage and it seemed to cause some disruptions, but nothing to serious since they had other hideouts. The younger guinea pig has recently started to bully the older one, teeth chatter, and force her out of the igloo. We have them separated via a barrier that they can still see each other and talk through, but I am not too sure what happened! Any help would be great.

TLDR: Younger guinea pig has started to bully the older guinea pig after they have been together since March and we have no idea why.

UPDATE 1: Today we decided to test the waters and remove the barrier. Everything was fine for about 5 minutes. They have 2 igloos now so we thought there would be no problems. They ended up getting into 1 and then started to fight and nip at each other and were teeth chattering for 5 minutes after they were separated. Their hair was raised, and even teeth chattered if we tried to pick them up. We have no idea what to do We would rather not have them separated all the time...

** I posted this on Reddit, but didn't get too many answers that could help me.

 

[Wiebke]

Hi all! First time question and Reddit in general! I thought I knew a good amount of information regarding guinea pigs, but something has happened that I cannot explain. I have 2 guinea pigs, both females. One is about to be 1 years old and is the second one we adopted, and the other one turns one in October. They were introduced in March and have been fine ever since! They got a long like sisters! Two weeks we introduced an igloo into their cage and it seemed to cause some disruptions, but nothing to serious since they had other hideouts. The younger guinea pig has recently started to bully the older one, teeth chatter, and force her out of the igloo. We have them separated via a barrier that they can still see each other and talk through, but I am not too sure what happened! Any help would be great.

TLDR: Younger guinea pig has started to bully the older guinea pig after they have been together since March and we have no idea why.

UPDATE 1: Today we decided to test the waters and remove the barrier. Everything was fine for about 5 minutes. They have 2 igloos now so we thought there would be no problems. They ended up getting into 1 and then started to fight and nip at each other and were teeth chattering for 5 minutes after they were separated. Their hair was raised, and even teeth chattered if we tried to pick them up. We have no idea what to do We would rather not have them separated all the time...

** I posted this on Reddit, but didn't get too many answers that could help me.

It sounds like your younger girl is trying to take over the lead, and your older girl is not putting up with it.
Please re-introduce them on neutral ground, but without a buddy bath, as they are not drenched in testosterone.
When you have them together please take out any hideys with just one exit, so there is less of a chance of tussles. It is often when one piggy feels cornered that fights can happen, just from the desire to get out at any price. It also prevents the dominant piggy to "lock in" in the other one. clean and completely neautralise the cage ant furnishings before putting them back.
Make sure that you have got everything in twos (hideys, bowls, water bottles), ideally at each end of the cage, so each girl can have her own territory and can get away from the other. I would recommend that you serve veg and pellets in smaller portions twice daily in two bowls, but remove them once empty. 80% of the daily food intake should be unlimited hay, so your girls won't go hungry in the meantime! Make sure that any hay access can't be blocked, either.
Introducing And Re-introducing Guinea Pigs
Dominance Behaviours In Guinea Pigs
Sow behaviour

After each separation, you will inevitably see dominance behaviour, so you have to accept that as they establish or re-establish a hierarchy. If they really cannot come to a consensus, then they would be better off next to each other or found a new companion each (like a neutered boar or a younger/submissive sow of their choice, ideally dated at a good rescue under expert supervision, so you come home with a new piggy only if there has been success). It is much rarer than with boars, but sow fall-outs can happen; once sows decide that the other one is "not us", i.e. part of her group, you've usually had it - whether they are sister that have lived together all their lives or not...

From what you are saying, your girls are a bit young for ovarian cysts; they can be an issue in middle aged to older sows. These are most often the reason for sudden aggressive behaviour in sows.

PS: How big is their cage?

As we have got members from all over the world, we find it very helpful if you please added your county, state/province or UK county, so we can tailor any advice to what is possible and doable where you are straight away. Click on your username on the top bar, then go to personal details and scroll down to location. In your case, your location very much determines any options you have if things don't work out.

 

[Michael]

Thanks so much! This is their playpen: All Living Things® Small Animal Playpen | Playpens | PetSmart

8 panels – 18 in x 29 in (45.7 cm x 73.6 cm) – 43 in (109.2 cm) dia

Alrighty so no bath and introduce them onto neutral ground. Should there be 2 hideouts with exits or just 1 in general? I changed my location to Orlando, FL and I do work at a PetSmart here too.

 

[Wiebke]

Thanks so much! This is their playpen: All Living Things® Small Animal Playpen | Playpens | PetSmart

8 panels – 18 in x 29 in (45.7 cm x 73.6 cm) – 43 in (109.2 cm) dia

Alrighty so no bath and introduce them onto neutral ground. Should there be 2 hideouts with exits or just 1 in general? I changed my location to Orlando, FL and I do work at a PetSmart here too.

The run is ample! Put up in a circle, it gives you better space for introductions without awkward corners.

There should be no hideys at all during the introduction on neutral ground and at least two with two exits during the dominance phase, which usually lasts more than one day. Chucking underpiggies out of a hidey is part of normal dominance behaviour as well as "locking in" an underpiggy; with two exits you prevent not just the bullying behaviour but also potential scuffles or fights.
If the hostilities/overall tension stay on a high level (but below an outright fight or nasty scuffle) I would separate overnight; if it is not getting better on the second day, I would consider calling it shots. they are in that case not very likely to become friends again.

Thank you for adding your location.

PS: The Guinea Pig Magazine has just signed up for being sold in the US via PetSmart; several forum members are contributors, me included.