It may be a bit pricier but I've used it for years without any issues. I never see fleas on dogs or in the house, never have an issue with worms, even in my girls aaafter whelp and their pups. I do repeated stool checks on pups and have never needed to worm.
I have a 14 month old boy that has never had a dose of wormer other than what he gets in the sentinal, he was stool checked just this last weekend.
I have used this product for the last two or three years on all my dogs. I love it even though it costs more. I have had no ticks and no fleas and no side effects.
Sentinel is a combo of Interceptor and Program. Program was one of the flea products on the market before Frontline/Advantage/Advantix, etc. It doesn't kill the fleas but it stops the cycle-flea birth control! Unfortunately it does nothing for ticks which are very bad(along with lyme disease) in my area. It is more cost effective for me to use Interceptor and Frontline.
