Advocate is only guaranteed to last for one month - frontline 2 months. I'm not too good about remembering and i'm sceptical about whether it's necessary, but Dylan is always picking up things outside so I was concerned about lungworm risk. If you use advocate you only need to worm infrequently as it covers most of the worms as well as fleas. Who knows if it's necessary??
We use comfortis, it's taken by mouth and isn't affected by water.
I do not believe that it does have to be taken every month regardless of fleas or weather. We use it when we start getting fleas (from out grooming dogs we get in mostly) We keep our dogs clean, and out bedding, so fleas are easy to see and eradicate, we feel no need to dose up our pack until their is actual fleas around. Just my opinion.
I use Milbemax as a wormer for Betty, its what the vet gives and has never made her ill. My friend gave his mini dachshund Drontal (she had also had Milbemax up to that time) and she was sooooooooooooooooooooooo sick, I think she was sick about 18 times in just under an hour) that I don't want to risk it on Betty when she's never had a single side effect from Milbemax.
I Frontline her every couple of months but am going to switch her to Green Dog as this should help with worms, ticks and fleas too.
I get the impression that Drontal seems to be worse with smaller dogs as the dosage is harder to get right. Having seen how sick my friends dog was there is no way I am giving it to Betty just in case! The good thing is with Milbemax is that she thinks its a dog treat and will give me a high 5 for it!!!!