Yes we used Activate for daughters Rott for about 1½ - 2 years till we lost her aged nearly 14. She was also on Soloxin - low thyroid, Devils Claw and a bioflow - arthritis, and Evening Primrose capsules , didn't quite rattle but they kept her going and comfortable. This was all after having her spleen removed aged 10! The Activate did seem to make a noticable difference to her for if she was 'with it' and if she was 'at home when the lights were on'
I've never had cause to use it on my own dogs but I've heard plenty of good reports about it, including one dog who was started on it for thyroid function - it was being caused by a problem in his brain, similar to early-onset dementia, and the aktivait sorted everything out.