B.T.
Jodi,
When you adopt from the Humane Society, the dogs are examined medically, all shots given, including fixing/spaying depending on the age requirement, and the adoption fee is supposed to cover all those preparatory treatments. This dog should not have been wormy. Please contact the HS and tell them of the difficulty.
I adopted an adult Aussie Shepherd several years and everything medical was included before I could even take the dog home. I've had no trouble with that dog in all this time.
They sort of "guarantee" them, and I'm certain they will take the puppy back if it's not working out, as that contingency is referred to in the adoption agreement. It it troubles me to think that someone there didn't take care of this before they released the dog to you, and you should definitely address this with them. HS is usually very user-friendly, wanting the very best for their dogs.
Best wishes!