We had a very large and very elderly dog who went blind, was also a bit doddery, but like Ben was well in himself. We felt, and our vet felt that he had a nice quality of life, snoozing on the sofa or in the garden, enjoying his food, not in pain and not frightened. On that basis we decided to let him continue and that went well until he had a vestibular attack which caused him to lose his balance very badly- and then he was distressed for a short time. Fortunately they don't last very long but we made the decisions if they started to reccur we would have him out to sleep. What eventually happened was he climbed on the sofa and and died very peacefully there entirely of his own accord- which we were all very grateful of. None of us regretted letting him wind down himself as he didn't suffer, and if your dog is well in himself then I'd wait a while yet personally, I'm sure you'll know yourself when the time is right. xxx