[anonymously]

I avoid the oral stuff, except for heartworm which I give every 6 weeks (not 4) in mosquito season only.
They are all pesticides, I use the least amount that I can to protect them. I have been using advantix II topical in the summer, but it depends on the dog, I have a small one that gets frequent baths, so I have gone back to alternating with preventic collars (amitraz).
I use deterrent “natural” sprays too…but I really don’t think they do much. They don’t kill the ticks/fleas.
I’d go all natural, but I lost a dog to Lyme and I don’t want to go through that again.

I don’t know when it got so complicated to own a dog. I’m leery of vaccines too. I decline them after puppy shots. But, there is still the rabies….

PS: I have never observed any adverse effects, but I have not used oral flea/tick preventives. One dog got a rash from the collar, so I can’t use it on him. He is elderly and doesn’t go far, so I just bathe him frequently.
I am sorry for your loss.