I hope Nemo is feeling better. It could be anything, I recently took my 3 year old terrier to the vet because he vomited 3X in 24 hours. Lab work was normal, negative for pancreatitis. The vet said he had a GI virus, he responded to prn Cerenia (the Pepcid did nothing). He got some sq fluids too. Whatever it was, it passed.
In my experience, dogs are more vulnerable after the age of 10. It sounds like you are giving him very good care. Try not to worry, sometimes less is better. Anything you give him has to go through the liver to get broken down and might make him more nauseous, that includes supplements.
