I have a rescue collie, she was just a pup and very poorly when we took her on. She was very nervous and anxious right from the start. We've had her for 14 months now. Long story short we've tried everything we can think of with her, plug ins, sprays, supplements, shirts, she's on medication etc. When I saw RelaxoPet Pro I ordered it with no expectations whatsoever. When it arrived I unpacked it, charged it and downloaded the app, the app was in German so I had no idea if it had been set up correctly, (I did contact RelaxoPet and they fixed the app so it's now available in English) I believe there is a silent mode but I use it with the music playing, it's like relaxing piano music to humans, I have no idea what the dogs hear but whatever it is it works! I now have a dog who is happy in the house and is out playing in the garden, she doesn't run straight back into the house if she hears a noise like people talking, car door closing, birds etc. My dogs level of anxiety was incredibly high, since using RelaxoPet Pro twice daily she's almost house trained (that has been a huge struggle, her fear of everything meant she was too scared even to go into the garden), she is like a different dog, she has an interest in toys and loves running around the garden with them, her appetite is good, she will even venture into the garden on her own which is absolutely amazing. The great thing is that it's a portable device so as her confidence at home grows we can take it with us in the car and venture further afield. I can highly recommend it if you have an anxious or worried dog. It's made a huge difference to our girl