Why did Novartis discontinue producing Program and Sentinel?

Dayna, There was a time when the facility where both were made was closed, however, Novartis has resumed production on both Sentinel and Program. While they are working to make enough to cover the demand created by their absence, Novartis has decided on a limited distribution. We currently carry Sentinel again, however your pet's veterinarian will continue to be the most likely source for Program until Novartis has been able to catch up to the demand. Thank you, VetRxDirect