Have you contacted vet offices and low cost neuter/spay clinics? Since he is intact and someone may be keeping him, the finder may go and have him neutered.
Jennifer
Posted on Craig's List, I emailed the owner suggesting our forum, BRAT, and the BRAT Facebook page:
http://nashville.craigslist.org/pet/2217332592.html
The ad reads:
Lost Basenji Dog (Mount Juliet)
Date: 2011-02-16, 8:49AM CST
Reply to: comm-zhnbh-2217332592@craigslist.org
Lost Male Basenji Dog on 2/15/2011 from home in Mt. Juliet. We live close to the police station and library off Mt. Juliet Road. Please call cell # 423-544-4423 if you have seen him. His name is Sunny. He is red and white, 30lbs, fixed, purebred Basenji with curly tail.
Location: Mount Juliet