Pancreatitis can be caused by a number of things. The main cause is usually diet related, too much fat. Other causes can include medications (side effect), stress, or just genetics as Yorkers are the most common breed to get it.
Early warning signs include picky eating with their normal diet, vomiting (especially with lots of white foam), and diarrhea/loose stools.
It’s very tricky to recover from as the pancreas is involved in digestion. You must fast and then slowly introduce food back with ultra low fat and higher carbohydrate foods like chicken, rice, plain white potatoes, egg whites, etc.
Here is a good article if you went to read more:
https://www.akc.org/expert-advice/he...titis-in-dogs/