It is important to determine if this is the case or the pup just has a urinary tract infection causing leaking.
Ultra sound or further tests can diagnose EU.
In most cases the pup will leak urine from birth. That was the case with one of our pups many years (30 plus) ago.
Surgery is necessary but type of surgery/cause of EU and when to do surgery will depend on age of pup and your vet will inform you of this.
Here is more info.