Barrio Dogs isn't exactly an adoption service — it's a nonprofit staffed entirely by volunteers dedicated to educating lower-income Houston neighborhoods about animal overpopulation, neglect, low-cost sterilization and state animal cruelty statutes. But through the Barrio Dogs Facebook page and Web site, the group often unites hardscrabble barrio strays with foster parents and, eventually, forever homes. If you follow Barrio Dogs on Facebook, beware: Some of the rescues' stories are hard to swallow, but they're made all the more worthwhile thanks to regular tail-wagging happy endings.