When I was working in the clinic, I was surprised at how many dogs came in suffering from pancreatitis. Quite literally, that means "inflammation of the pancreas". The techs working would tell me, 'it's because people are feeding their dogs crap'. I thought they were almost kidding, yet our animals often suffer from so many things we can prevent, for example diabetes in cats. Cats, in nature, don't get fat. I've heard many people suggest we are to blame for their acquisition of Diabetes Mellitus.
The pancreas is an amazing organ with many functions. One of them, is to secrete digestive enzymes our bodies need to digest our food. The idea is that the pancreas, due to any number of disruptions, over produces those digestive enzymes and begins to digest itself. Those digestive enzymes, as they autodigest the pancreas, cause abdominal pain, vomiting, anorexia, fever, and dehydration (to name a few).
While there are some other factors which may cause it such as certain drugs, tumors, and trauma, the largest school of thought is that it's fatty foods. Dogs who are obsese, and/or consume high fat diets are at risk. At the clinic, we saw instances of dogs suffering from pancreatitis following fatty-food holidays. Fourth of July, Thanksgiving, Christmas.. Our dogs eat dog food and healthy snacks typically, but sometimes we allow them to feast on hot dogs and other fatty items their bodies are not used to. Thusly, we see an increase amount of cases following our holidays. We think our dogs are just like us. In many, many ways.. they are. But our bodies are used to the crap we put in them, our dogs' bodies are not.
I have asked many people "how much" fatty junk would it take to cause pancreatitis, and the answer has always been the same: it depends. I have had vets tell me a couple of hot dogs did it for a particular dog. Other dogs, maybe much more. Bottom line is, don't risk it. It's bad enough we eat it, keep your dogs on healthy food.
This condition is treatable, but will most likely require your dog be hospitalized and put on a 'no food' diet until their digestive system and pancreas can calm down and return to it's natural function.
Remember, our dogs love snacks and treats, but they are pretty happy with anything we give them. Pass them some fruits and veggies, and they will likely be just as happy. They will be extra happy to skip on hot dogs and avoid getting pancreatitis!