Interceptor was a brand-name heartworm preventative product distributed by Novartis Animal Health. Interceptor was reformulated to protect against not only heartworm but also fleas and other parasites, as well. Th product is now sold under the brand name Sentinel.
Sentinel contains the same active ingredient, milbemycin oxime, as its Interceptor predecessor. But it also contains the drug lufenuron, which helps prevent fleas from attaching to and infesting dogs. Additionally, the monthly dosed, veterinarian-prescribed chewable tablet works to prevent infestation by other parasitic worms. Like any heartworm preventative medication, dogs require testing for worms before they can begin a Sentinel regimen. Follow all veterinarian recommendations.