I used some of the flea treatment that you rub between the cats shoulderblades. i had purchased it over the counter between visits to the vet figuring it was a generic version of frontline. I was so wrong! it made both of my cats sick and lethargic and caused scabs and hair loss wherever the product touched their skin. reading some of the other stories i’ve seen on the net i am so glad their reaction wasn’t worse. this stuff should be illegal to sell.