You're speaking to Dr. Michael Salkin. Welcome to JustAnswer. I'm currently typing up my reply.
Thankfully, the proton-pump inhibitor antacids such as lansoprazole are very well tolerated by dogs. Even 60 mg isn't expected to cause adverse effects in your puppy. As with ingesting anything unusual transient gastrointestinal distress in the form of inappetence, vomiting and/or diarrhea can arise but your pup wasn't intoxicated. There's no need to induce emesis or treat in any manner.
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