[107barney]

Here is my advice.

I would use the Frontline because there is a flea problem in NYC and also a tick problem, and the information you're googling about isn't what I would call scientific or reliable. I've been using it for 14 years without a flea, tick, or side effect/problem. I've been using it for almost 6 years on my epileptic dog as well....

Sentinel or Heartgard are both fine. I used interceptor for years (that's sentinel without the flea component) and it was discontinued. I almost went to sentinel but because I still need a tick med, I switched to heartgard. It is safe for small dogs.

You could also use Revolution which is dosed by weight. The holistic people tend to like that one a little more than the others (not sure of their rationale) but I think the better products are the Heartgard +/- Frontline.