Weird black spots appeared on my rat?

Hey guys, one of my girls is not doing too good. We have taken her to the vet where she received painkillers, antibiotics and an infusion to boost her system. In the last few days we have given her further treatment that we receibed rrom the vet (same stuff she got there).

About 2 days ago she could barely move and her balance was off a lot.

Shes doing a lot better now but we noticed that small black/brownish spots started to appear around her body and we have no idea what it could be. Have you guys seen anything like this?