Hi,
I just read this thread and from just reading the first one I was thinking he might be sick.
My Buffy has a heart murmur and on bad days when she has a lot of liquid build up on her chest she will drool in her sleep and a runnie nose, but no chest swet.
I hope what ever caused this, passes fast and he is well soon.
By the way everyone it doesn't hurt to have a First Aid Book for Dogs on hand and read thru it when you can.