Rating: 
Hill’s Prescription Diet I/D Canine dry dog food is not rated due to its intentional therapeutic design.
The Hill’s Prescription Diet I/D Gastrointestinal Health product line includes only one dry dog food. Although the formulation appears to be designed for dogs with digestive health issues, we found no AAFCO nutritional adequacy statements for this dog food on the Hill’s website.
Hill's Prescription Diet I/D Canine
Dry Dog Food
Estimated Dry Matter Nutrient Content
Ingredients: Whole grain corn, brewers rice, dried egg product, chicken by-product meal, corn gluten meal, pork fat (preserved with mixed tocopherols and citric acid), powdered cellulose, lactic acid, dicalcium phosphate, chicken liver flavor, iodized salt, potassium citrate, choline chloride, calcium carbonate, potassium chloride, dried beet pulp, soybean oil, vitamins (l-ascorbyl-2-polyphosphate (source of vitamin C), vitamin E supplement, niacin, thiamine mononitrate, vitamin A supplement, calcium pantothenate, biotin, vitamin B12 supplement, pyridoxine hydrochloride, riboflavin, folic acid, vitamin D3 supplement), taurine, minerals (ferrous sulfate, zinc oxide, copper sulfate, manganous oxide, calcium iodate, sodium selenite), preserved with mixed tocopherols & citric acid, phosphoric acid, beta-carotene, rosemary extract
Fiber (estimated dry matter content) = 2.6%
Red items when present indicate controversial ingredients
| Estimated Nutrient Content | |||
|---|---|---|---|
| Method | Protein | Fat | Carbs |
| Guaranteed Analysis | 26% | 14% | NA |
| Dry Matter Basis | 26% | 14% | 52% |
| Calorie Weighted Basis | 24% | 30% | 46% |
The first ingredient in this dog food is corn. Corn is an inexpensive and controversial cereal grain of only modest nutritional value to a dog.
For this reason, we do not consider corn a preferred component in any dog food.
The second ingredient includes brewers rice. Brewers rice is a cereal grain by-product consisting of the small fragments left over after milling whole rice. Aside from the caloric energy it contains, this item is of only modest nutritional value to a dog.
By the way, contrary to popular belief, brewers rice has nothing to do with the process of brewing beer.
The third ingredient is dried egg product, a dehydrated form of shell-free eggs. Quality can vary significantly. Lower grade egg product can even come from commercial hatcheries — from eggs that have failed to hatch.
In any case, eggs are easy to digest and have an exceptionally high biological value.
The fourth item lists chicken by-product meal, a dry rendered product of slaughterhouse waste. It’s made from what’s left of a slaughtered chicken after all the prime cuts have been removed.
In a nutshell, chicken by-products are those unsavory leftovers usually considered “unfit for human consumption”.
In addition to organs (the nourishing part), this stuff can contain almost anything — feet, beaks, undeveloped eggs — anything except quality skeletal muscle (real meat).
On the brighter side, by-product meals are meat concentrates and contain nearly 300% more protein than fresh chicken.
In any case, although this item contains all the amino acids a dog needs, we consider chicken by-products an inexpensive, lower quality ingredient.
The fifth item is corn gluten meal. Gluten is the rubbery residue remaining once corn has had most of its starchy carbohydrate washed out of it.
Compared to meat, glutens are inferior grain-based proteins lower in some of the essential amino acids dogs need for life.
This inexpensive plant-based ingredient can significantly boost the total protein reported on the label — a factor that must be considered when judging the actual meat content of this dog food.
The sixth ingredient is pork fat, a product from rendering pig meat.
Commonly known as lard, pork fat can add significant flavor to any dog food. And it can be high in linoleic acid, an omega-6 fatty acid essential for life.
Although it may not sound very appetizing, pork fat (in moderate amounts) is actually an acceptable pet food ingredient.
The seventh item is powdered cellulose, a non-digestible plant fiber usually made from the by-products of vegetable processing. Except for the usual benefits of fiber, powdered cellulose provides no nutritional value to a dog.
The eighth ingredient is lactic acid, a nutrient found naturally in many living organisms. It’s likely added here to adjust the pH of the product which (in turn) reduces the growth of unwanted biological contaminants.
From here, the list goes on to include a number of other items.
But to be realistic, ingredients located this far down the list (other than nutritional supplements) are not likely to have much of an effect on the overall rating of this product.
With four notable exceptions…
First, we note the use of beet pulp. Beet pulp is a controversial ingredient… a high fiber by-product of sugar beet processing.
Some denounce beet pulp as an inexpensive filler while others cite its outstanding intestinal health and blood sugar benefits.
We only call your attention here to the controversy and believe the inclusion of beet pulp in reasonable amounts in most dog foods is entirely acceptable.
Next, the product includes soybean oil is red flagged here only due to its rumored (yet unlikely) link to canine food allergies.
However, since soybean oil is high in omega-6 fatty acids and contains no omega-3′s, it’s considered less nutritious than flaxseed oil or a named animal fat.
Thirdly, we find no mention of probiotics, friendly bacteria applied to the surface of the kibble after processing to help with digestion.
Finally, the minerals here do not appear to be chelated. And that can make them more difficult to absorb. Non-chelated minerals are usually associated with lower quality dog foods.
Hill’s Prescription Diet I/D Dry Dog Food
The Bottom Line
Even though this is a prescription product, our review has nothing to do with the accuracy of claims made by the manufacturer as to the product’s ability to treat or cure a specific health condition.
So, to find out whether or not this dog food is appropriate for your particular pet, you must consult your veterinarian.
With that understanding…
Judging by its ingredients alone, Hill’s Prescription Diet I/D appears to be a below-average dry dog food.
But ingredient quality by itself cannot tell the whole story. We still prefer to estimate the product’s meat content before concluding our report.
The dashboard displays a dry matter protein reading of 26%, a fat level of 14% and an estimated carbohydrate content of 52%.
And a fat-to-protein ratio of about 53%.
Below-average protein. Below-average fat. And above-average carbs when compared to a typical dry dog food.
Yet when you consider the protein-boosting effect of the corn gluten meal, this looks like the profile of a kibble containing only a modest amount of meat.
Bottom line?
Hill’s Prescription Diet I/D is a grain-based dry dog food using a modest amount of dried egg product as its main source of animal protein.
However, due to its intentional therapeutic design, this dog food is not rated.
Special Alert
Rice ingredients can sometimes contain arsenic. Until the US FDA establishes safe upper levels for arsenic content, pet owners may wish to limit the total amount of rice fed in a dog's daily diet.
A Final Word
The descriptions and analyses expressed in this and every article on this website represent the views and opinions of the author.
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However, our rating system is not intended to suggest feeding a particular product will result in specific health benefits for your pet.
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Remember, no dog food can possibly be appropriate for every life stage, lifestyle or health condition. So, choose wisely. And when in doubt, consult a qualified veterinary professional for help.
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Notes and Updates
01/04/2010 Original review
08/10/2010 Review updated
05/24/2012 Last Update
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