Rocket Dog Rescue volunteer Kay Hoskins rode her 1970s-era bicycle up to the ACC shelter on 15th Street. Her job is to find foster homes for dogs on the verge of euthanasia. She's an energetic woman with brown hair that falls on the shoulders of her black sweater, which has a light patina of dog hair. Her green eyes widen slightly when she talks about saving the dogs with behavior problems, the misunderstood dogs she calls "angels."

"Last month we took a dog that nobody wanted because it nipped at people, and guess what? She's living with a new family and she's an angel," she says.

Hoskins was visiting two dogs she's trying to find foster homes for: Chunky, a five-year-old Labrador-shepherd mix, and Oliver, a three-year-old pit bull mix. She checked in at the front counter and then headed to the kennels. After spending time with Chunky and Oliver in their runs, she walked along a concrete walkway to look at the recent arrivals. Hoskins stopped in her tracks at the run of a young female border collie with a healthy gold-brown coat. The dog was excited to have a visitor and struggled to stay in a self-imposed sitting position while Hoskins read her chart.

The dog's time was about up. She was due to be put down within a day or two, maybe sooner, depending on space. "She doesn't have a name," Hoskins says. "She must have been a stray."

She unlocked the run door and stepped in. The dog nuzzled Hoskins' thigh and then stood on her hind legs, gently wrapping her forepaws around Hoskins' waist. "She's an angel," Hoskins says. "Did you see how she put her arms around me? Is Butterscotch too corny for a name? It fits her coloring."

Hoskins stepped out of the run and reread the newly christened dog's chart. Butterscotch is apparently good with people, but behaves poorly with other dogs.

Hoskins went back out front to ask for a "dog-to-dog" demonstration. Maybe the behavior problem was manageable. But a kennel attendant named Betsy advised against it. Butterscotch's reaction to other dogs was so strong, she might redirect aggression at her handler.

Hoskins was not ready to give up. She put a temporary hold on Butterscotch so she could make some phone calls.

In the heyday of the SF/SPCA's no-kill movement, a dog like Butterscotch would have had a chance to work with a certified dog behaviorist who had the space and resources to possibly make a difference in her behavior. But the SF/SPCA has shifted its focus to a large animal hospital, which is under construction just across the street. Now dogs like Butterscotch have become impractical.

Hoskins sat on a bench outside and talked with Rocket Dog Rescue's founder, Pali Boucher, who was out of town. "I know ... I know," Hoskins said into her cell phone. "All right. No, I'll tell them now. Bye."

Boucher puts complete faith in the kennel attendants, especially Betsy. Rocket Dog Rescue does not have kennel space to isolate a dog with Butterscotch's behavior problem, and it's too risky to put her in a foster home.

The late afternoon sun is warm, and Hoskins lingers before going in to talk with the clerk. "I'm not the one who usually does this. Pali usually denies the dogs," she says in a soft voice. "This is tough because I know what it means, and she's such an angel."