I have a 15yr old collie lab a rescue who had a bad 1st 9 years but a happy 6 years with us, with hopefully more to come, at around 14 he started to age quickly and was mentally not so swithched on, aktivait has really helped, he seems happier in himself and more alert, he also seems a little more spritley on walks, friends also noticed the differene in his behaviour and asked how we'd achieved it. Most people I've spoken to also say they have had fantastic results, if you have an old dog who is slowing down mentally I cannot recommend it enough.