Goodness know if this is supposed to be in "super furry animals" or what, but I just wanted to vent. 
I have two female gerbils aged around 2 and half - had them 14 months now, got them from a local breeder/rescuer who had introduced them to each other as adults. In all this time they've had the odd dominance squabble but nothing major until now. But I came home today and they seem to have had a proper fight and injured each other - one has a torn back toe/claw and the other is favouring one of her front legs. The pale one is quite bloody around her neck/shoulders but it's hard to tell if they have any more wounds or if it's from cleaning the injury I can see. I'd imagine toes might bleed quite a bit. They're used to me but still don't like to be picked up by hand and I don't want to stress them any more than necessary to closely examine them.
They weren't actively fighting when I got home but I separated them straight away to be sure, and I've adapted a plastic bin cage as a split cage (with two wire cooling racks - DIY solution on advice of the rescuer I got them from!) to keep them in while I assess the situation. They are both moving about okay and I've seen them eat and drink, and they aren't behaving overtly aggressively towards each other - lots of curiosity and nose touching through the wire. I'm hoping they've just had a spat and it's not a complete falling out of their clan partnership, and that if I switch them around in the split cage for a few days and let them heal up and sort themselves out they can go back in together.
It was just really upsetting to see them all bloody and looking very woeful and sorry for themselves, and now they are sulking quite a bit - their plastic bin cage is quite small compared to their adapated aquarium, and I suppose I should also hope it's partly because they're separated and maybe they actually miss sleeping together and grooming and other gerbilly activities. Fingers crossed they'll be okay after a little time apart.