If it is blood, then she does need to go to the vet to find out what is going on and potentially get more treatment - there are a variety of conditions which can lead to blood in the urine.
All you can do is the routine home care of daily weight checks to keep an eye on hay intake and syringe feeding as appropriate. This will obviously not treat an illness though.
Emergency and Crisis Care as well as Bridging Care until a Vet Appointment
In terms of you having kept them apart during the illness, do note that it is not recommended to do this. Piggies should always be kept together, even when one is unwell.
Keeping them separately will not prevent the other from catching any transmissible illness because they would have been together before symptoms were showing in the first piggy and it may already have been passed on anyway.
Separating them causes a lot of stress to them which can lower the immune system and therefore make fending off and fighting any illness a bit harder.
Another issue why medical separations are not recommended is the impact it can have on a bond. They have the potential to cause two piggies to refuse to go live together again after the illness.
Have they been living side by side during their separation?
I would recommend you reintroduce them.
If they have been living side by side then with any luck their bond is still alive as they would still have been communicating. It does not guarwntee they will be able to share a space again, but it Is a staff.
If they haven’t been side by side, then I would put them side by side in separate cages for a few days to allow them to get used to each other again.
Either way, you must go through the proper neutral territory reintroduction rebonding process (after a few days living side by side in separate cages again). This always needs to be done on neutral territory to allow them to decide if they still like each other and are able to live together again.
Do not just put the piggy back into the original cage as this will be seen as a territory invasion and can cause them to fight.
If they go back together in neutral territory for several hours, then clean out the cage they are to live in and after a few hours, you can move them back to the cage.
If the rebonding does not work, they would need to remain in separate cages.
Bonding and Interaction: Illustrated social behaviours and bonding dynamics
