What Happens When You Deworm A Puppy Confused About Dewormed Puppy?

Confused about dewormed puppy? - what happens when you deworm a puppy

My dog is wormed 13th July for the family, which they sold to us. We have 20 July. After a few days we have noticed his stool was very loose. That brought her to the vet for a stool sample. They just started to get rid of worms in their stool. Why is this happening now when on 13 has been dewormed? takes time? He also spent twelve days since dewormed.