Recent Domination behavior.

Question
Nearly a year ago, I recieved a guinea pig as a gift for my birthday. After reading that day about their well-being and care, I went out the next day to get a second guinea pig as a companion, (I managed to get his brother who hadn't been sold yet.) As soon as I introduced the two, they seemed to be fine. Right off the bat, they would lie side by side snuggled up together, cheek to cheek. But starting maybe two months ago, out of nowhere, they started exhibiting a lot of domination behavior, one more than the other. They can't cross paths without making that low growl sound and trying to climb on top of eachother.

So heres my question: Any idea what might be causing the domination stuff out of nowhere? Is there anychance of bringing back that bond that they had before?

Answer
Hi Tim

As pigs get older they become sexually mature so they are more likely to exhibit dominance behaviour and can cause issues between 2 pigs that previously were fine.

However, if the worst is that they are rumbling/mounting there is nothing to worry about and this should settle down within a couple of weeks.

Andy