Here’s the thing
Here’s the thing, all pet treatments won’t be effective if you don’t remove the infestation indoors and outdoors … We had a big flea problem that lasted a year , Seresto works to keep off new fleas , kills them and stops the breeding cycle , my cats have used various treatments but I like the collars because some of the spot on treatments ( prescription) caused chemical burns on one of my boys . Buy authentic collars though! They work for my cats but you have to sort out the environment first.