Purina doesn't make anything natural!!! IMO, Purina doesn't make anything considered FOOD! If this is Pancreatitis, it's dangerous/deadly, & he should be checked by his Vet......Shaking is a sign of pain, drooling is a sign of poison, so it must be intense for your guy!
Any chance he could have gotten into something poisonous? If you are completely sure, then you must evaluate his food.....There are many Purina products making animals very, very ill or even worse.....
Let his digestive system rest for at least 12 hrs. with only water or broth.....Then cook a bland diet of chicken & rice or chicken & sweet potatoes.....Serve small portions a few times a day......
Don't feed ANY Purina products.......See your Vet ASAP
Here's a link to read...Consumer complaints still ongoing:
http://www.consumeraffairs.com/pets/ralston.html
Let us know how he's doing......Karla
P.S. DON"T buy any of the foods your Vet is going to try to sell you, either!!!
Did this just start, not be going on for days?
Sounds like a vet visit is in order. If it gets worse it could mean need for emergency medical attention.
If this started after changing the type food, don't give him any more. It may be a food allergy, but that doesn't mean he will be able to resolve it on his own. Allergies can be dangerous.
Sorry I can't give you an easy to implement cure.