I have two litter sisters. It is the worst combination apparently but I didn’t know that when I got them and it would have been difficult to decide which one to rehome if I had gone down that route.
Your dogs are at the age when they are maturing and it could be the increased hormones that are causing the bickering.
My girls always got on reasonably, tolerating each other rather than liking each other. As they have gotten older the bickering has got worse.
Stevie was originally the more dominant sister and Marley accepted this but the dynamics have changed over the years.
Marley is a resource guarder and we have to make sure that there is nothing that she can guard and if we see her with a ‘prize’, we quickly take it off her. Luckily she will let us ‘depower’ her.
Over the years, we have learnt to recognise what can start a spat. I can’t fuss Marley if Stevie is present as she will fly at Stevie if she get too close, I can’t groom her if Stevie is in the same room as it will start a fight. These situations can be handled easily as we just put them in separate rooms on these occasions.
When they were younger, I did try to separate them when they were fighting but this meant any issue they had was not resolved. I now leave them to sort themselves out. This may seem irresponsible but the fights stop as quickly as they started.
All of my family now know how to avoid potential trigger points but they are all adults. It would be vey dangerous if a child did get in the way of the fights as when the dogs are in full fight mode they are in another zone and would be oblivious of anyone getting in the way.
My girls are now 11 and so over the years we have become familiar with their moods. Most of the time they live peacefully side by side but they don’t really like each other just tolerate each other. I guess its like human siblings, some are the best of friends, some never speak to each other.
Dog spats sound horrific but often the noise is worse than any damage that is done.
I think you have to consider if the whole of your family are able to recognise and prevent clashes in the future. It can be very tiring to be on constant alert and is it fair on your children? Are they of an age when they are able to quickly get out of the way if the dogs are fighting?
Only you can decide if you are willing to keep both but they are both young and the rehomed one should adjust quickly if you do choose to do that
I wish you the best of luck with whatever you decide. Keeping both can be done (my two are 12 this year) and the good times have far outnumbered the bad occasions.