Lucas aka Mr. Pretty uses Frontline. I've never had any problems using it. Do make sure you put it on every month to keep the ticks away. It keeps fleas away for 3 months, but in the summer the ticks are out like mad, so I use it every month from April to September.
I use Frontline on my cat too, but I swear I think he's like Reagan from the exercist. I have to keep him on my lap for at least an hour after putting it on him. He can lick the back of his neck...creepy kitty. =)
You can usually find the topicals like Frontline cheaper online rather than buying from your veterinarian. Just be sure you get it from a reputable place.
