My cat has long hair and I didn’t realize that the Hartz Flea collar that I put on her was doing damage to her skin and health. A few days after putting the Hartz Flea collar around her neck I was petting her and noticed something different about her neck. When I checked I found that her neck was completely raw. If I hadn’t noticed this, she would have had an infection that may have taken her life. I took her to the vet that same day. I was just very lucky to have noticed this considering her long fur. Always, always, always, just for the next few days after putting a flea collar on, check to make sure that your pet is not having a bad reaction to the flea collar. This can take the life of your pet, or cost a lot of money in return vet bills just to clear up an infection. I learned a very sad lesson the hard way. I hope you are not reading this after this has happened to your pet. I wish I would have read the label more carefully and I wish the lable would tell people to check their pet daily for the next few days. I feel this would have not happened to my pet if I read that I should check my pet daily after putting the collar on. I feel bad about what I did to my precious pet. She is fine now and very happy. I never use a flea collar on her now and I only use the flea care from my vet.