In Switzerland, it’s illegal to own just one guinea pig. This is because guinea pigs are social animals and they are considered victims of abuse if they are alone
As a gerbil owner this is a constant dilemma for me aswell. One tends to always die much sooner than the another and it breaks my heart seeing the other be left alone. If I then get another one then the same thing is just going to happen again due to their age difference and if I get two there's like 50% chance they don't get along and now I have two terrariums with one gerbil in one and two in the another.
If anyone else is considering getting gerbils my advice would be to either get 3 males or go with a hamster instead since they live alone. I currently have 3 females but I almost had to separate them earlier due to fighting. This is less likely to happen with males.
I'm interested in how this works in terms of pairing.
I have a lone guinea pig. I had two rescue pigs that were rescued from a bad situation, and one sadly died after 6 months. We've had two separate partners, but despite a lot of work in trying to partner them up he's never been able to not fight a potential cage partner.
I want him to have a partner, but the stress for both of being constantly in fight or flight is concerning. We even considered rehoming at a rescue centre and giving a huge donation, but it would just pass the problem on.