My Dog Is Lost ... Please Help Find Him

Please help if you can - my daughter's dog slipped away from the dogsitter while she was out of town. He's not wearing a leash or collar but has a harness on. This happened on Saturday, February 19th. Here is her message:

"My dog is lost! 7-8lb Yorkshire Terrier, Tan and Brown, very small and friendly. Answers to the name of "Diddy" and responds favorably to treats. Please help me find my beloved little dog - he's not built for the streets! Last seen running near 4200 13th Street in NE Washington, DC. Please keep an eye out to see if you see a dog that fits this description anywhere on the street, or possibly being carried, someone may have rescued him but not known who/where to contact."

We have done everything we can think of, including notifying shelters, contacting service providers, filing a lost dog report, and using online sites such as petfinder.com, yelp.com, pet911.com, lostmydoggie.com and others, including Facebook and DC Craigslist.

Please reply here or if you see any dog resembling Diddy, or can offer any advice or assistance. Thank you so much.

Details:

Yorkshire Terrier, Male
Pet Color: Brown and Tan
Pet Age: 5 years old
Pet Weight: 8lbs
Date Lost: 02/19/2011
Missing Address: 4210 13th Street NE 20017
Washington, DC 20017
Reward: Yes