I began using the Hartz drops on my german shepherd three months ago. Unfortunatly, I did not connect his recent health problem to the Hartz until I put on the third months drops. My dogs lips have been bleeding and raw. His entire lips have peeled off in solid long strips of skin. They are cracked and bleeding. I could not figure out what was going on. I took him off all dairy thinking it may be an allergy to his all time favorite treat which is cheese. Stopping dairy did not help. Anyways… I put the drops on two months in a row as the directions stated. The third month I was about 2 and a half weeks late administering the drop. I had noticed that his lips had been healing finally but I was still not sure what had happened or what had caused it. Well, When I put that the third dose of Hartz drops on, by that evening, my poor dogs lips were peeling off in chunks, bleeding and raw. I felt so bad. I realized at that point that it was the Hartz product that had caused the problem. It was too late because I had already put the drop on. We had to go through it one more time. It has been two months now and I have not used this product. I am happy to report, Jaeger, my shepherd is doing just fine. NO MORE HARTZ!!!!!!!