Quad Dewormer for Dogs is a broad-spectrum dewormer that removes common intestinal parasites with a single dose.* Quad Dewormer is effective against roundworms, hookworms, tapeworms and whipworms in dogs over 4 weeks old. *Steps should be taken to control fleas and rodents on the premises in order to prevent reinfection; otherwise, re-treatment will be necessary. Consult your veterinarian for assistance in the diagnosis, treatment and control of parasitism.