Thanks for the tip, I have been using a DAP collar for a month and I must say it helped my girl be calmer. Getting to the end of the month period after which I have to replace it (and I have noticed that that tends to whine a lot when she sees that I am about to leave her with my "dogsitter"). I will put this type of collar on for another month as when it is "working" she stops trying to steal food and being agitated. I was told by the vet to use it for another month and then take it off for a couple of days at a time so that she wouldn't get too used to it! Difficult to know f I can leave it on all the time as I have a very anxious dog, perhaps the diffuser is best but I don't really know what is best. However, thanks for the tip, half the price of what I paid last month.