Hi! I've been fostering for many years & we have, on occasion, dealt with Upper Respiratory issues. Many times the antibiotics helped, sometimes they just had to get through it (viral)! One thing that our vet recommended was a good probiotic during the time they were sick.
As for cleanliness, we bleach EVERYTHING here (whether they are sick or not). I put all their toys in linen laundry bags, bleach all rags, towels, bedding, cubbies, anything we use when they are sick (old tees, old shirts) in a HOT bleach wash. We do this all the time, just as a regular course of action. In addition, between litters, we use a bucket of hot water with bleach & wipe down the cages & let them air dry. I also make sure that their bowls are changed & washed in our dishwasher daily. We also wash our hands ALOT.
When we have sick babies, and we have a few around here every year, I make sure to keep up with their weights, we weigh them at least once a week & if I don't see them eating daily I reweigh. We also do our best to snuggle with them as much as we can when they are sick. My husband is wonderful with the little's who are sick - he gets them right up in the crook of his neck & puts a little rag or piece of a baby's blanket over them (they calm right down & snooze for awhile). They really bond with him & he just loves it!!!
We also give them as much high calorie food as possible when they are sick - mother's milk, canned kitten food (as much as they will eat) & make sure the Mom is well hydrated and fed with kitten food, too.
Just as an FYI, Clorox wipes will fit into a Swiffer mop - it is a nice thing when you are worried about viruses & germs!
#FosteringaPet