He does sound lost, rather than abandoned, but you’ve done right thing in checking for a chip, leaving your info at the pound, etc..
That he was wearing a sweater and is so friendly probably means he’s been well-cared for, which helps to make him a good pet for where serendipity seems to have taken him—to your household!
We had a basset hound in my early years, and she couldn’t have been more tolerant of us small children—she actually loved the attention.
I have a basset. He’s almost 12. When he gets out, my boys and I have had the honor of chasing him all over the surrounding neighborhoods. He’s like houdini and once he smells something, he’s gone. He probably wasn’t abandoned, there’s just no telling how far from home he really is. They are sweet, stubborn dogs. Great with kids.
I agree with others who urge you to keep looking for the owner. What if a small child is crying herself to sleep every night?
Try Craigslist. There are forums there for lost and found pets. When I lost my dog, I posted it on Craigslist and got a good tip from someone who saw him.
Long story short - A week later I found Shadow. He had been picked up by Animal Control.
He is part Golden, Border Collie, and some sort of Hound. When I walk in the door or squeeze a squeak toy he goes to howling- a lot like a Basset Hound, in fact.
Abandoned!
Public (street) Rescue years ago of a German Short Hair that was birdy and impeccably trained to hunt and obedient. I had no kennel/yard so left her in the apartment to go to class. Returned to a DESTROYED home. Couch cushions (all of them) shredded, drapes down and shredded, twin bead mattress shredded and defiled, you get the idea. All accomplished silently, according to the neighbors on each side and upstairs.
As long as she was accompanied the picture of a dream dog and upland bird buddy—
A part of the education I didn’t pay tuition for in college.
No Separation allowed.
Bless you for your kindness. I had a thought that possible the dog belonged to someone elderly who might be having a hard time advertising or even knowing where to start. You might try an old fashioned ad in the local newspaper, in case the owner is not computer savy.
As others have commented, it does not sound like he was abandoned. Too well cared for. I would tend to think he’s lost/ got away from owner or maybe someone who was watching him for the owner...