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
Rou was lost earlier today-6/5 in East Aurora in the neighborhood of Murphy Creek. Aurora is a suburb of Denver. He is microchipped and wearing a blue collar with tags that have his name and the owners phone number.
If they have not found him, I hope a search party can.
Here is the ad:
http://denver.craigslist.org/pet/3059738875.html
Jennifer
The Craigslist ad has been deleted, so I have to hope it is because they found him.
It was posted on Facebook that he had been found safe and sound
Happy ending !