I keep my dogs on K9Advantix which is by Bayer(same company that makes Advantage). Living in Florida, we are under constant assault by fleas, ticks, and mosquitoes. The K9Advantix formula goes on the skin behind the shoulders and protects them for a month from reinfestation by fleas and ticks, or mosquito bites. Advantage only protects against fleas, and Frontline protects against fleas and ticks.
I have used all three products on differing occasions and none of these resulted in any side effects or irritation for my animals. If I've been slack and forget to give them their dose at the beginning of the month, they get fleas. But after noticing and applying the Advantage/Frontline/K9Advantix the infestation disappears within a day or two.
I would recommend any of these products
, depending on what parasites are common in your area. Even though the K9Advantix is more expensive, I take my dogs running in the woods and there are fleas, ticks, and an entire air force of mosquitoes waiting for us, so I keep them on that and they are happy and itch-free.
You can get these through your vet. I hope this helps!