Dog Missing

Tinker is missing!  We were stacking wood last night and he is now missing.  I am guessing he wandered up by the highway and someone picked him up.  Unfortunately I took his collar off the other day when I was putting on his flea meds and didn't put it back on.  My stomach hurts and I have not slept all night.  He is 9 years old and my baby.  He sleeps with me every night and normally he isn't too far from me.  When I am gardening he is usually laying down the next row over, when I am working in the kitchen he is ALWAYS underfoot.  I just don't know what I am going to do.