I applied PetArmor to my Lab about a week ago. He started scratching violently and I thought it would wear off. He did not even have any fleas--I was using this as a preventative. What should I give him? He is miserable and also has developed a lump under his leg, one of the places he is itching severely. I just started researching PetArmor and there are some lawsuits because their pets died. What can I do to help him? This is such stupidity that you can't even trust what you buy at the store for $40 or $50 dollars. Can anyone help me with this? Should I give him Benadryl? How much? He weighs 115 lb. Thank you.