Get them to the vet. It is likely somewhat related to worms or something that is transmittable through a shared liter box. Either way they need treatment.
Blood in a cats urine may be a sign of a bladder infection or kidney problem. You should take your cat to the vet straight away, as it may be suffering or in pain. Kidney infections are quite common in cats and can be easily treated, but do need professional attention.
If your cats have blood in their urine, there are a lot of things that could be wrong. One possibility is a urinary tract infection, which can be very serious. You should take them to the vet as soon as possible.
This is a sure sign of a urinary tract infection and can be determined by a vet examining a fresh urine sample. The animals will need to be put an antibiotics and you might well consider changing their diet to one that specifically helps reduce the risk of further urinary tract infections.
