My cat, Onyx, has a very bad flee problem. Two months earlier we used the Hertz flee drops on him. He was very agitated and restless. At the time we thought he wasn’t used to the feeling of the drops. Fast forwarding to last week, we decided to use a Hertz flee collar. While wearing the collar he would scratch at his neck, again we thought it was normal and he was just trying to take it off. Two days ago, Tuesday night, my mom decided to give him a shower but used a flee comb instead. However, on Wednesday morning, when she prepared him for a bath she noticed a patch of his hair missing and in it’s place was a bloody, bright red chemical burn. After closer inspection, we noticed it was all around his neck. We researched what was wrong and under further investigation we found this site and the various stories exposing Hertz products for what they really are. Please dispose of all Hertz products and instead go to your local vet and ask for a recommendation. We hope this doesn’t happen to any other pets.