I lost 3 cats due to using sergeants gold flea spray. all were healthy cats.First one showed reaction within 30 min was rushed to vet, died few hours later, 2 others died within a few days, this occured in Jan this year.The stress of seeing my cats die without being able to help them was beyond words. a class action is being filed.vet said never use this kind of over the counter product it has toxic ingriedients in it. i had always used frontline but couldn’t afford it at the time. my cats never had a problem with that.