Your vet said the word pancreatitis, and now the bag of food in your kitchen feels like a suspect.
Everyone has an opinion about what to feed next, and almost nobody shows you the numbers.
So I pulled them. Three veterinary low-fat diets, every figure the brands print, and the one calculation that puts them on the same footing.
The short answer. Your vet chooses the diet, and the three below are low-fat dry veterinary foods sold in the US. Per 1000 calories, Hill’s i/d Low Fat works out to about 19 g of fat, and Royal Canin and Purina print ranges of 16 to 28 g that overlap it.
The labels cannot say which is leanest. What can protect your dog every day is simpler: no scraps, no fatty treats, small weighed meals.
At a glance
Through your vet
Through your vet
Through your vet
What is going wrong inside
The pancreas is the kitchen that prepares the enzymes your dog uses to digest dinner. In pancreatitis that kitchen becomes inflamed, and it hurts.
Dogs often vomit, go off their food, seem tired or have a sore belly. It can be a sudden attack or a long-running problem, and only a vet can tell which.
It is usually not what is in the bowl
When researchers looked at what dogs with pancreatitis had been eating, the clues were rarely the kibble. They were what happened around it.
None of this proves that a given food is safe. It does mean the cheapest protection is a lid on the bin and a rule about scraps.
Miniature Schnauzers are a special case, because they often have high blood fats. Our Miniature Schnauzer food guide covers that research.
The number on the bag does not tell you much
Three bags print fat in two different ways. Royal Canin and Purina print a range as fed, 5% to 9%. Hill’s prints a dry-matter average, 7.4%.
Dry matter takes the water out, so it can look leaner or fatter than the as-fed figure next to it. The percentages cannot be compared.
The fix is to count fat per 1000 calories. It removes water and calorie density from the picture.
One Purina veterinary article gives a recommended range of 10 to 14% fat on a dry-matter basis, or 2 to 3.5 g per 100 kcal. That is 20 to 35 g per 1000 kcal, the shaded band below.
Hill’s does not print fat per 1000 kcal, so I calculated it. Its page gives 7.4% fat in dry matter and 3511 kcal per kg. Dry kibble holds between about 5% and 12% water, which puts as-fed fat at 6.5% to 7.0% and the answer at 18 to 20 g.
That sits close to the 18.6 g veterinary low-fat diet fed to 16 Miniature Schnauzers with high triglycerides in a 2020 study. I do not know which product that study used, so the line is context and not a target.
The cup trap
Here is the number that matters most if your vet ever switches you between these foods. A cup of Hill’s holds 319 kcal, Purina 295 and Royal Canin 247.
Scoop for scoop, Hill’s delivers 29% more calories than Royal Canin. Weigh the food, and use the feeding guide for the food you are actually pouring.
The three diets in numbers
| Food | kcal per cup | g fat per 1000 kcal | AAFCO basis |
|---|---|---|---|
| Hill’s i/d Low Fat | 319 | about 19 (calculated) | Feeding tests |
| Royal Canin GI Low Fat | 247 | 16 to 28 | Formulated to meet |
| Purina EN Low Fat | 295 | 16 to 28 | Formulated to meet |
I did not feed these to a dog, so there is no taste test here. I read each brand’s own page or label, copied the numbers as printed, and marked as calculated anything I worked out myself.
Over-the-counter foods are left out on purpose. I could not source figures for any of them that I would put next to a veterinary diet, and the choice is your vet’s.
The diets one by one
Each card shows what is printed on the brand’s own page or label. Hatched bars are dry-matter or calculated figures, and a pale bar shows a printed range up to its maximum.
Hill’s Prescription Diet i/d Low Fat Canine
Dry · veterinary diet
The only one of the three backed by AAFCO feeding tests, and the highest in calories per cup.
Dry · veterinary diet · AAFCO feeding tests · 3511 kcal per kg
Full details
Hill’s prints average nutrient content on a dry-matter basis, so there is no as-fed fat on the page. I worked it out from the figures it does give: 7.4% fat in dry matter, less 5 to 12% water, over 3511 kcal per kg, lands at about 18 to 20 g of fat per 1000 kcal. The first ingredients are brewers rice, corn protein meal, chicken meal and chicken by-product meal. A 319 kcal cup is the richest of the three, so a scoop that suits one of the others will overfeed here. Your vet can supply it or send a prescription to a pharmacy.
Royal Canin Gastrointestinal Low Fat
Dry · veterinary diet
Lowest calories per cup of the three; fat per calorie is a range because the label prints one.
Dry · veterinary diet · Formulated to meet AAFCO · 3210 kcal per kg
Full details
The label prints fat as 5.0% minimum and 9.0% maximum, so fat per 1000 kcal can only be bracketed at 16 to 28 g. Fibre is the highest here at 4.8% maximum, with psyllium husk and fish oil on the ingredient list. The first ingredients are brewers rice, chicken by-product meal and barley, and moisture tops out at 10.5%. At 247 kcal a cup it is the lightest of the three, so the same scoop delivers fewer calories. Your vet can supply it or send a prescription to a pharmacy.
Purina Pro Plan Veterinary Diets EN Gastroenteric Low Fat
Dry · veterinary diet
Highest protein of the three; fat per calorie is a range because the label prints one.
Dry · veterinary diet · Formulated to meet AAFCO · 3209 kcal per kg
Full details
The label prints fat as 5.0% minimum and 9.0% maximum, with fibre at 3.0% maximum and moisture at 12% maximum. It is formulated to meet AAFCO nutrient profiles, which is not the same as proven in a feeding trial. The first ingredients are brewers rice, barley, corn protein meal, poultry by-product meal, animal digest and beef fat. Your vet can supply it or send a prescription to a pharmacy.
Living with it at home
Questions to take to your vet
- What fat level are we aiming for, and how will we know it is working?
- Do we recheck blood fats, and when?
- How many meals a day, and for how long?
- Which treats, if any, are safe?
- Can you get the brand’s typical analysis behind a printed range?
When to call the vet
Call your vet or an emergency clinic if your dog is vomiting, very tired, has a sore belly or refuses food. Do not wait to see whether it passes.
Pancreatitis can be serious, and treatment starts with a diagnosis, not a diet change.
Frequently asked questions
What is the best food for a dog with pancreatitis?
There is no single best food, and your vet decides. Vets commonly choose a low-fat, highly digestible veterinary diet, and this page compares the printed figures for three of them.
Which of the three has the least fat?
Per calorie, Hill’s i/d Low Fat works out to about 19 g of fat per 1000 kcal, which is my calculation from its dry-matter figures. Royal Canin and Purina print only ranges of 16 to 28 g that overlap it, so the labels cannot settle the order.
How much fat should be in dog food for pancreatitis?
Your vet sets the target for your dog. One Purina veterinary article gives a recommended range of 10 to 14% fat on a dry-matter basis, which is 20 to 35 g per 1000 kcal.
What foods can trigger pancreatitis in dogs?
In a Texas A&M case-control study, dogs with pancreatitis were more likely to have eaten unusual food, table scraps or rubbish before diagnosis. Fatty human food is the thing to keep away from your dog.
Can a dog with pancreatitis eat grain-free food?
Grain-free is not a measure of fat. Check the printed fat figure and ask your vet before choosing any food for a dog with pancreatitis.
How often should a dog with pancreatitis eat?
During recovery, a veterinary nutrition article from Purina advises small meals four to six times a day. Your vet will tell you how long that lasts for your dog.
Is homemade food better for pancreatitis?
Not by default. A homemade diet needs to be balanced and low in fat, so ask your vet about a board-certified veterinary nutritionist before you cook for a dog with pancreatitis.
This is a research comparison, not a hands-on test. Figures come from each brand’s own page or label unless noted, and may change when a recipe changes.
As an Amazon Associate I earn from qualifying purchases, which costs you nothing extra. This page is general information, not veterinary advice.
References
Hess RS, Kass PH, Shofer FS, Van Winkle TJ, Washabau RJ. Evaluation of risk factors for fatal acute pancreatitis in dogs. Journal of the American Veterinary Medical Association, 1999;214(1):46-51. Read the abstract.
Evaluation of dietary factors associated with spontaneous pancreatitis in dogs. Texas A&M University case-control study, 198 cases and 187 controls. Read the abstract.
Xenoulis PG, et al. Miniature Schnauzers with hypertriglyceridemia fed a veterinary low-fat diet. Journal of Veterinary Internal Medicine, 2020. Read the paper.
Michel KE. Pancreatitis, canine. Purina veterinary nutrition article (edition and year not listed). Read the article.
Product figures: Hill’s Prescription Diet i/d Low Fat Canine dry; Royal Canin Gastrointestinal Low Fat; Purina Pro Plan Veterinary Diets EN Gastroenteric Low Fat label. Purina’s moisture figure is from a retailer listing.
