The dog may well have been lost,but I seriously doubt he was abandoned. Hunting dogs get off on a trail sometime,and don't know when to stop following it. Sometimes it's the next day and they are miles away before they give up,and by then their masters have given up looking for them and gone home.
I live in a rural area,and it's pretty common for stray hunting dogs to show up in my yard,looking for a human to help them. Most have collars with their owners names and phone numbers,so they are no problem. Sometimes they have collars missing name tags and phone numbers,and I just call the SPCA to come get them. In fact,I had to do that for a beagle/basset hound mix that showed up lonesome and hungry in my yard not long ago. Very nice,very friendly dog,but lost.