Do I always need to seek the guidance of a veterinarian when giving my dog medicine?

In short, yes. While there are medications out there that are relatively safe for dogs, most of the time, you do want to reach out to your veterinarian because not every dog is the same.

Since she's asking the veterinarian, the answer would be yes. Even if I wasn't asking the veterinarian, Google should say, ask your veterinarian.