Hi Dan,
As many have mentioned, keeping him as active as possible will do him wonders... my parents signed me up for all kinds of sports... swimming, soccer, basketball, ice skating lessons, cross country skiing, etc. Don't be afraid to send him out if it isn't a perfectly sunny, bright 70 degree day... but do make sure that he is appropriately bundled up for the weather, and if he gets wet from rain/snow, get him dry quickly.
I think that living with CF is all about balance. You cannot kill every germ in your house, or protect him from every germ at school. At the same time, he needs to wash his hands, and dress warmly when its cold, and do the little things that help keep him healthy.
Nutrition is important... I could not imagine getting a five year old to drink a scandi-shake every day... they taste terrible... I can barely put them down now. However, you can make sure that he gets a CF healthly diet that is high in protein, etc. I'd recommend lots of ice cream, and cooking with butter.
Another key recommendation that hasn't been mentioned is chest physical therapy. If your son isn't already doing airway clearance, I'd recommend talking to his dr. about it. CPT is preventative - it will keep mucous moving, preventing plugs from developing which lead to compromised lung function and infection. Any airway clearance technique is better than nothing.
Here's why I like Chest PT:
1) I find the vest ineffective compared to chest pt.... I know that others like the vest, this is just my personal experience.
2) Breathing devices - the acapella/ flutter/ etc. do not do enough to help the smallest airways. These are also the hardest to keep clear... Chest PT wins.
3) I know that my dad benefitted greatly from doing chest pt. It was the major tangible, daily activity that he could do for me to help me fight CF. Doing this helped him deal with any anger/ guilt/ etc. issues he has experienced as a CF parent, and brought us closer together. My dad and I did chest pt from when I was 7 until I left for college at 18. (he still does it whenever I'm home for holidays, etc.) I don't think a lot of 13-17 year olds spend 50 minutes a day with their dads. Chest PT made us spend this time together.
4) Doing chest PT (or the vest) every day, even when he is healthy, will get him into a routine of care while he is young. Even if he doesn't have to start taking nebulized treatments for several years, having a time of day set aside for "CF stuff" it will make it easier for him to comply with his treatment schedule.
Finally, as parents, you are your child's best advocate. Learn as much as you can about CF. Do not be afraid to question Dr.'s. Do not be afraid to change Dr's if you feel they are not treating your son's CF as an individual case, independent of every other patient. Do not acquiesce to Dr.'s orders without learning the benefits, the risks, and the alternatives. For example... my family moved from VT to upstate NY - at my first visit to the new clinic (I was 7 at the time), the Dr. told my mother that I needed IV's. My PFT's were in the 100's, and I wasn't culturing anything. When asked why I needed this treatment, the Dr. responded "we give all our CF patients at least one course of IV's every year." Now... there are lots of opinions about how aggressive CF treatment should be, and I'm not taking any sides, but my mother was not a subscriber to this ultra agressive theory. She took a stand, and did what she thought was right - We left the clinic, and for the next 10 years, made the 6 hour drive back and forth to the VT clinic for the next 8 years, until there was a staffing change locally.
As your son gets older, you will have to help him learn how to take responsibility for his care. I don't know how my parents did this, but I do know that I grew up knowing that my CF treatments were not optional, and that the only way to have a life that was "as normal as possible" was to do my treatments.
Anyway, just a few thoughts... sorry for the long post.
Chris
25 w/ CF