Which dog’s attention did Billy get when he tried to explain about the bet?

Billy "got" Little Ann's attention.

“Sweetheart,” I said, “you must do something for me tonight. I want you to tree the ghost coon for it means so much to Grandpa and me.”

She seemed to understand and answered by washing my face and hands.

I tried to talk to Old Dan, but I may as well have talked to a stump for all the attention he paid to me. He kept walking around sniffing here and there. He couldn’t understand why we were waiting. He was wanting to hunt.