If you are seeing worms in your pet's faeces despite using VetBox products correctly please contact us and we will be able to offer advice.
Unlike flea products, the worming treatments will kill only the worms that are present on the day of treatment and have no lasting efficacy.
Theoretically your pet could go out the next day and pick up a worm infection.
The recommended schedule of treatment for worms is every 3 months for adult cats and dogs according to the World Veterinary Small Animal Association (WSAVA).