There often are indications of dehydration in cats with pancreatitis because they may be vomiting or not be drinking well. (texvetpets.org)
The majority of cats with pancreatitis do not vomit or have diarrhea. (2ndchance.info)
According to one recent study in cats, though, only 35 % of cats with pancreatitis showed vomiting and only 25 % appeared to have abdominal pain. (urbananimalveterinary.com)