B.B.
I have 2 daughters, and my oldest daughter has battled croup/strider on the tail end of just about every cold she's had. Yes, you can have strider-ish symptoms and croupy cough without much of the cough.
I'm really surprised he didn't go ahead and prescribe the steroid or at least give a breathing treatment (nebulizer).
Get a cool-mist humidifier for his bedroom.
Keep close tabs on his breathing, and if it gets too labored, take him to the hospital. (Getting him outside in the cool night air will also help.)
When you get to the hospital, what they'll likely do is give a steroid (Orapred?) and breathing treatment, then send you home with a script for the steriod.
For what it's worth - and good luck!