Just wanted to share my observations and a few chats I've had with my dog training guru.....
This time round on the wheel of fortune, our vet has been pushing the Advocate 'back of the neck' treatment for the new pup - duly I gave it a go.
Maybe 1-2 days later I could noticeably see a change in pups temperament - he was v. much more aggressive toward the family and JP when out. When I spoke to my trainer he was not surprised and reeled off a number of clients with all types of dogs who'd reported the same thing - apparently there is plenty of anecdotal evidence on the net about this (I've not checked).
What I would say though - we have dropped this treatment and gone back to the old faithful, Frontline - pup is calmer and not affected in any way.
This is not meant to be controversial - rather, a pointer (no pun intended) for anyone who may have seen a deterioration in behaviour every four months or so and is incidentally using this particular product - I will also add said product did what it said on the tin, obviously.
Hope this helps