Local vets recommended frontline however I am finding the frontline spot on drops are no longer working effectively for fleas longer than max of two weeks most likely because our two cats love to groom each other. Like any product, they can have a reaction with your pets, same with humans can have a reaction to medications just have to look out for it and be aware. I noticed other bayer companies, drontal and advantage have other spot on treatments but I guess it depends what works for your pet I am giving a collar a go this time. Hopefully a good solution for our cats :)
Not a fan of the Bayer collars. Tried once on my 2 cats, both had severe neck burns/blisters, a common reaction says my vet.