Maybe you should ask the vet on how much Benadryl for her to take. Lucee was on it for 7 days. She took 50 mg. twice a day .Which is more than Tom and I take at a time. Our pills were 25 mg each. I also called the company to confirm that they were in fact only 25 mg. So for me one pill last over 12 hours, but for dogs it's different. Lucee is 40 pounds. It did not seem to help. She was on Cephalexin 250mg twice a day for 14 days and that did the trick for her scratching. She DID NOT have hot spots though. She did have dandruff and scabs, and seemed to itch ALL over.
Katz