>the tablets I use for the adults last longer then the puppy liquid wormers

Nor sure what you mean by this???
The puppy liquid wormer
I use can be used for adults too and the pack advises to worm adults 3-4 times a year! Of course you can worm your dog today and take him out Saturday and he can infect himself all over again ;) As
I understand it, the 3-4 months interval is to prevent the dog becoming overburdened with worms.
Is there a wormer which prevents the dog from having worms in the first place rather than just killing the worms off?