Call the veterinarian that examined him and ask that he call you back (today) when he has a minute. If the vet tech speaks to you, that’s nice, but I would insist on speaking to the veterinarian. Puppies can go downhill quickly, he may need subq fluids and IV medication (not a big deal) to get over the hump. I don’t know what testing he has had but more may be indicated to properly diagnose and treat.
It is not unusual to call within 24 hours of a veterinary appointment with additional questions or concerns. Be prepared to bring him back in……if you wait till after hours the emergency clinic will be your only option.
Let us know what happens.
