you could try to aspirate his nose and but him in the bathroom with a steamy shower for a bit. I'm not sure if I would give him Benadryl though. Make sure he drinks lots and lots of water. Ice cubes in the water dish might help. The canine influenza in going around and vets are calling it Kennel cough. I hope he gets better soon. let him rest, I'm sure he doesn't feel good.