Once the dog begins taking the medicine for hookworms the hookworms should be killed off within 24 hours to 48 hours of beginning the medicine.
However the hookworm medicine for dogs only kills off the adult hookworms and not the hookworm eggs but as those eggs grow into adult hookworms then the hookworm medicine for dogs will kill off those hookworms as well.
It can take up to 2 to 4 weeks and sometimes as long as a few months of the dog taking the worm medicine for all the hookworms to be killed off.
The dog should not have to take anymore hookworm medicine to kill off any more hookworms after being hookworm free for a few months.
The dog will only need to take hookworm medicine if they have hookworms.