>I understand that they can last anywhere from 9 to 18 months. How can >you tell when they are wearing off? My vet has recently ordered deslorelin implants as well. Our plan is to put in an implant every 12 months (along with a melatonin implant) whether symptoms have returned or not. If symptoms seem to be returning any sooner, we will implant sooner. This is the same procedure we have always followed with 4-month Lupron injections. We have always stuck to a rigid schedule, not waiting for symptoms to return. I believe that waiting for symptoms to return is too hard on the body. Katharine Florida [Posted in FML 6606]