Loki is looking fantastically good tonight, he's been playing with his toys and has eaten his dinner (he was starving poor boy!). Lubo is also doing well albiet a little grumpy (but then thats Lubo!). Lenny is actually not too bad this evening and has not been sick since teatime tonight so fingers crossed its just the last hurdle.
The boys do share absolutely everything and have since they were wee - food bowls, beds, litter trays etc. The only seperation was when Loki was in the vets on a drip at the weekend! I've thrown out all their current food bowls and replaced these (just in case), washed all the bedding and absolutely scrubbed their bedroom. I'm really loathed to separate them but do hear what you say and if things do not pick up in the morning then yes it sounds like my only option

Vet has not suggested this up to now.
Roz, I have introduced Nova (female bengal - 16 weeks) into my household - Christmas Eve to be exact. She has had 2 brief false start introductions. One because we discovered she had conjunctivities and the second one the evening before the boys took ill. I have discussed Nova's entry to the household with my vet (who has checked her over) but he seems reluctant to accept that Nova has infected the boys as she is not displaying any symptoms - I've kept her isolated anyway so not sure what others think.
The other theory I explored was my rescue Stitch. She has been with us well before we got the boys but I wondered whether or not she could have picked something up outside (she is an outdoor girl) and brought it into the house? Again vet seems quite dismissive as Stitch is fighting fit.
When we picked Nova up we did go to the breeders, is it possible that although Nova is not infected we could have carried the infection back to the boys? She is a fairly large breeder with a number of cats although I would add we did not make any physical contact with any of them but were in their presence.
Thanks in advance for any advice.