Wormshield is distributed by Banfield. Isn't that the Vet clinic's inside Pet Smart? It is for Hook and Round worms also. Not sure that it is really necessary for a mostly house dog to have to be medicated for Hook and Round worms monthly? Just my opinion
From this site
WormShield for dogs (provided exclusively by Banfield), which prevents heartworm from developing, as well as treats and controls roundworms and hookworms.