Yea, had a nearly identical situation with a previous dog in his late 11's. He made it to 14. He was on Lasix and something else. Around the 13 mark his stamina dropped off drastically and the murmur got so bad you could hear it at night if the house was real quiet.
I don't think there's any real pain involved with CHF. Their circulation just goes to hell and they get tired really quick, but the poor buggers still want to go, go, go. The meds will definitely help, but her hunting days are probably numbered.
