I use a scalibor collar. I used to use frontline spray but one of my dogs had a bad reaction to it right out of the blue. Even with a good spray routine, I would still have to remove both attached and walking ticks from the dogs on a daily basis. I have used the scalibor collars for 7 years now and once the first 5 days are over, I have never had one tick on either dog, not one. Given that they are walked in the New Forest which is full of the blighters and a hotspot for Lyme disease, I think that is pretty good. They are not so suitable for dogs who swim frequently as they are said to poison water wildlife. The collars are also licensed against fleas in the US but not here. My concern about the tablet is that the tick has to attach to be killed, scalibor kills/repels walkers as well; also if you give the tablet and the dog has a reaction to it, there is nothing you can do. With a collar, spray or spot on you can remove it or wash it off