I have a GSD and about a year ago she developed an itchy skin. I took her to the vet and he said that there was nothing wrong, and it could be something she picked up, so I bath her and it stil pervailed ,  She has her tick/flee the fist of every month, and I groom her most nights, and have not seen anything that may cause this, I took her back to the vet, and he has taken a skin sample and sent it for analysis, and I'm waiting for the results. I've tried your Grasmilben-Ex itchy skin, but with little joy.  If you have any other product I could use , please let me know,  Many thanks Mr Berry.