Mine are on year round prevention.
I only deworm if needed. I have lots of pups, and we travel alot, but never had a problem, other than occasional tapeworms. I have fecal tests done twice a year on the ones that travel, once a year on the others. I use plain ivermectin for Heartworm prevention.For those of you who don't give it year round -- are you worried about intestinal parasites? Do you worm monthly with another product? That's my main reason for 12 months of Interceptor. If there's another option I'd be very interested.