New puppy was dewormed, might still have worms?

i just adopted one and its vet records say it was given treatment for de worming by panacur i think was the medication, anyways it says this was done for 5 days on the 12 of june, if i just adopted it today but it has been in the care of a shelter, do you think it could still have worms or do u think the de wormer from the 12 probably worked? hes still going to the vet for a checkup no matter what, just asking for opinions