Shuddering Piggy

Question
Hi! I got an abbysinnian guinea pig (Peanut, female) when she was about 6 weeks old for christmas from my boyfriend. I've had guinea pigs before so I know they dont like to be on their own so in January I got another abby pig (Tigger, female). There is only about 6-8 weeks age difference between them. As I didn't want Peanut to become territorial with Tigger I bought a brand new cage and introduced them in the new cage. Peanut let Tigger know she was the boss to start with but things calmed down and they got on really well. Now its getting to be warmer weather I have moved them to an outdoor cage. But since this has happened in the last month or two I have noticed that Tigger seems to be bullying Peanut. Tigger shakes her body from side to side and makes a shuddering noise. This is happening quite frequentely and I've noticed a couple of scabs on Peanut where I think Tigger has had a nip. I'm just wondering if this is normal? I thought it could be because as they are reaching adulthood they are sorting out the "pecking order" between themselves again? Or if I should be thinking about spliting them up? Many Thanks Catherine.  

Answer
Hi Catherine

The shuddering, usually accompanied with moving of the back legs is, as you say another example of them sorting out who is boss. This has started again because there is new territory (cage) for them to decide who is boss of.

The best advice I can give you is to keep a close eye on them and if there is any violent scuffles separate them. However, from what you say, it hasnt got to this stage yet.

Andy