I recently purchased 2 collars for my 2 cats. I took the collar off my one cat because she seemed to be acting strangely. My Chloe seemed to be fine with it on. Last Wednesday into Thursday she was acting lethargic and not her self. Thursday morning she passed in my arms. I took my healthy cat Roxy into the vet to have her looked over considering what had just happened to Chloe. I was told to NEVER use these products on cats!! They cause neurological issues leading to death. Moral of my is that my sweet Chloe was poisoned!! My healthy cat is now on medication to cleanse all of the toxins out of her body due to this hideous collar!!