I’ve used Frontline for years on my dog. It apparently has become ineffective as the last 2 doses did not keep my dog from becoming infested with fleas. From what I’ve read some vets here in New England have said the same thing and my groomer has seen this in other clients. The flea collar Seresto has been suggested. I recently purchased one and the battle goes on. I ‘think’ it is working but wanted your opinion on these new collars.
I still need to do more research in this topic. This is because almost all peer-reviewed articles recommend topical flea drops for pets (I think it’s because flea drops provide more coverage on the pet’s body than collars. Collars may be suited more for prevention than control). So, I’ve spent more focus on the compounds within these products.
Seresto collars contain the same active ingredient, imidacloprid, as is in Advantage flea drops. Imidacloprid is also fairly comparable to fipronil in Frontline. These compounds are adulticides, meant to primarily kill adult fleas. There haven’t been any documented cases of resistance to the compounds. Still, it is possible that it exists.
The other compound in Seresto collars is Flumethrin, which is a pyrethroid insecticide. This is another adulticide.
The main ingredient that differs between Seresto collars and flea drops is an insect growth regulator (IGR). For example, Frontline contains methoprene, and Advantage contains pyriproxyfen. IGRs mimic natural insect hormones that regulate development. Exposed eggs and larvae can’t reach adulthood. However, for pet treatments, the real advantage is that exposed adult females are sterilized and can’t lay eggs. So even if they survived the adulticide, they couldn’t lay eggs to continue the infestation with a new generation.
Regardless, it seems like many pet-owners are satisfied with the Seresto collars.
Sorry I couldn’t provide deeper insight at this point.