Just in case you are looking for a diet alternative. I have a home-made recipe book for dogs - there is a section on 'dogs with gastrointestinal or pancreatic disease' - which would be low fat, 6 different recipes. My Oscar was on one of them before he passed away two weeks ago. It helped so much, just wish he would have been on it a long time ago (only on it for 3 weeks).
Author is in Canada (not sure if you can get it in America) - Hilary Waton
Complete & Balanced 101 Healthy Home-Made Meals For Dogs
(need to also buy the supplement - Balancer)
She is fantasic. If you are interested you can check her web-site and email her to see if it is carried in America.
THE BALANCER Home-Made Meal Supplement for Dogs
Good luck!