Hello all! I'm brand new to the forums, and after combing the internet I couldn't find any practical advice for my situation that wasn't just basic info regurgitated on every site that comes up with a Google search.
My girlfriend and I had 2 male chins that got along fine. One is 8 (Jack) and the other is a little over a year old (Bandit). They went through the side-by-side introduction back in February and after a week or so they were best friends. They slept together, groomed each other, etc.
Recently, we bought 2 more male chins (rescued them from a PetCo since they had been in a tiny glass box for a year straight) and we want all 4 to get along eventually. The 2 new chins (Churro and Chimi) also get along just fine and they are total sweethearts. None of the 4 are hyper-aggressive, and they all respond well to treats and human contact.
My girlfriend made the mistake of trying to immediately introduce all 4 simultaneously before even having their cages near each other for a bit. It started out ok, but Bandit soon started running around and "attacking" Churro and Chimi. No serious biting or blood, but he would pull out clumps of their fur with his mouth. We split them up into their respective cages and are now trying to introduce them slowly.
One thing I am worried about is that Bandit is now being aggressive to Jack and the two of them don't sleep together or play together anymore and spend their time on different levels of their cage. It's 7.5' tall and has 8 or 9 levels, so it's plenty big enough for them to have their own space. I just worry that the introduction of the new chins has ruined Jack and Bandit's dynamics and I don't want that to happen.
We have a playpen we normally use for Jack and Bandit and we are using that as the neutral ground for the actual introductions. We have tried putting Churro and Chimi's cage inside the playpen to see if cage within a cage works (it didn't), and now we are at the point of considering just doing 1 on 1 intros with different combos of chins and hope that eventually all 4 get along. My girlfriend put Jack and Chimi together in the playpen yesterday for an hour and they got along fine.
If it helps, the summary of how things stand is: Jack is (or was) the alpha over Bandit in that pair, and Chimi is the alpha over Churro in the second pair. Bandit does not get along with Churro or Chimi, and is now being aggressive towards Jack. Jack and Churro compete for dominance by boxing and squeaking when they are together. Chimi and Churro are still getting along fine. Jack and Chimi seem to be ok. When the cages are next to each other, Bandit will sit near Chimi and Churro so they're only separated by the few inches between cages, and Chimi and Churro seem to be welcoming to Bandit. Jack tends to hide out on the uppermost level of his and Bandit's cage, and typically does not sit near the other cage or chins. There are so many chin personalities, and I'm at a loss of the best course of action to try and establish a happy chin family.
If anyone has advice on the best way to bring two pairs of male chins together, please let me know!