Rating: 
Hill’s Prescription Diet R/D Canine (dry) gets the Advisor’s second-lowest rating of two stars.
Currently, the Hill’s Science Diet R/D Canine line includes two dry products… each designed for weight reduction in overweight dogs.
- Hill’s Prescription Diet R/D Canine
- Hill’s Prescription Diet R/D with Chicken Canine
Hill’s Prescription Diet R/D Canine was selected to represent both products for this review.
Now, before we begin, please keep in mind…
The veterinary dog food reviewed here may or may not be suitable for your particular pet. Moreover, it is certainly not the intention of this report to act as a substitute for sound medical advice.
Just the same, we firmly believe it is our responsibility to share our honest opinion regarding the quality of the product’s recipe… as well as its individual ingredients.
Hill's Prescription Diet R/D Canine
Dry Dog Food
Estimated Dry Matter Nutrient Content
Ingredients: Ground whole grain corn, corn gluten meal, chicken by-product meal, powdered cellulose 10.4% (source of fiber), soybean mill run, soybean meal, chicken liver flavor, dried beet pulp, soybean oil, iron oxide, dl-methionine, l-lysine, potassium chloride, vitamin E supplement, 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), choline chloride, taurine, minerals (manganese sulfate, ferrous sulfate, zinc oxide, copper sulfate, calcium iodate, sodium selenite), l-carnitine, preserved with mixed tocopherols & citric acid, beta-carotene, rosemary extract
Fiber (estimated dry matter content) = 13.5%
Red items when present indicate controversial ingredients
The first ingredient in this dog food is whole grain corn. The fact this item is whole grain is not the issue. No, the corn used here is usually pet-grade… unlikely human quality.
Although there’s no way to know for certain, this can be the same kind of corn used to produce feeds for livestock and therefore frequently contaminated with insects, mites and molds.
Many claim corn causes chronic canine allergies. But those allergies are probably more a result of what’s in the corn… than the corn itself.
The second ingredient reveals corn gluten meal. The gluten is the rubbery residue left after corn has had all its starchy carbohydrate (the good stuff) removed from it.
Compared to meat, glutens are inferior grain-based proteins lacking many of the essential amino acids dogs need to sustain life.
Because of its top position on the ingredients list, this plant protein item accounts for much of the protein reported in this dog food.
The third item reports 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… those unsavory and inedible leftovers deemed “unfit for human consumption”.
This stuff can contain almost anything… feet, beaks, undeveloped eggs… you name it. Not a quality ingredient.
The fourth item is cellulose… a non-digestible plant fiber usually made from cotton or wood (no kidding… wood).
Cellulose fiber is added to dilute the number of calories per serving and to give the feeling of fullness when it is consumed.
Except for the usual benefits of fiber, powdered cellulose provides no nutritional benefit to a dog.
The fifth ingredient is soybean mill run. Mill run is a by-product of the creation of soybean meal. This is nothing more than a cheap, low-quality filler.
The next item mentions soybean meal. Soybean meal is actually another by-product of soybean processing.
Soybean meal contains 48% protein… inferior plant-based protein. So, like corn gluten, it (too) has the ability to inflate the protein content of this dog food product.
Also, the minerals listed here do not appear to be chelated. And that can make them more difficult for a dog to absorb. This can be yet one more sign we’re probably dealing with an inferior product.
Hill’s Prescription Diet R/D Canine… the Bottom Line
This Hill’s Prescription Diet R/D Canine weight loss product is a real disappointment.
The dashboard reveals a dry matter protein reading of 34%, a fat level of 8% and an estimated carbohydrate content of 50%.
You may have noticed the carbohydrate content reported by Hill’s does not agree with our figure. That’s because the company uses a special method1 that deducts the fiber from its “carb” estimate.
But because fiber is still a carbohydrate, the 50% level reported by our dashboard is probably closer to the true amount in this food.
Now, on the surface, the protein reading of 34% gives the initial impression that this might be an above-average dry kibble.
But don’t be fooled by that number.
When you allow for the protein-enhancing effect of the corn gluten and soybean meals, there’s not nearly as much meat-based protein present as what’s reported here.
Plus… the abundance of inferior Red Flag ingredients also serves to lower our confidence in the overall quality of this dog food.
With only two-stars, Hill’s Prescription Diet R/D Canine may not be the best choice for your dog… or your money.
Not recommended.
Some Final Thoughts
Remember, no dog food can possibly be appropriate for every life stage, lifestyle or health condition. So, choose wisely. And when in doubt consult your veterinarian for help.
Have an opinion about this dog food brand… or maybe the review itself?
Please feel free to share your comments below.
- Nitrogen-Free Extract Method ↩
{ 4 comments… read them below or add one }
IF YOU DON’T RECOMMEND HILLS DIET R/D FOR DOGS.
WHAT DO YOU RECOMMEND. PLEASE ADVISE WHAT FOOD IS BETTER
Hi Fran… thanks for the excellent question. Just about every dog food company makes a weight management product… but (as you’d expect) all are not equal.
To narrow your choices, click on the menu tab at the top of our website called “Tag Cloud”. Then click on the phrase “Weight Management”. This will present a list of brands reviewed on our website that contain at least one weight loss dog food.
As you click on each, remember these are brands… and not the specific products made by those companies. Click on each review until you find 3, 4, or 5 star brands and then look for the name of the weight loss product in the list near the top of each review.
This should give you lots of choices. Hope this helps.
Dear Mike,
Like many other fools, I trusted my veterinarian to recommend a good food for my older Cairn terrier with pancreatitis. She sold me r/d (canned.) After reading your site and others, I transitioned her to Innova Senior (canned) and am working on getting her over to Wellness Core Reduced Fat (dry), as it is more convenient than canned.
Today, because of another flare-up of the pancreatitis, I went back to the vet and showed her the Innova Senior Can (with no byproducts and no cellulose). After reading the can, the vet got all defensive and had the nerve to tell me that “objectively speaking” the Hills was an “excellent reputable food,” that pork by-products were an excellent protein source” and that cellulose is a perfectly acceptable fiber source. I was floored, and felt like asking her “Well then, why don’t you just enjoy a can for lunch?” It was as close as I have ever been to having a fight with a veterinarian.
So, I e-mailed Hills asking them to justify the use of pork byproducts, cellulose, soy mill run, etc. in a dog food designed to help sick dogs and which costs about $2.50 a can.
Is there no-one in veterinary schools paying attention to the ingredients? Are dog food manufacturers who use these controversial and inferior ingredients just heartless? Are they at all interested in doing the right thing?
All this is by way of thanking you and the other concerned folks who take the time to help us navigate the confusing dog food world.
Hi Ed… thanks for sharing your experience. You certainly did the right thing by discussing your choice with your vet. In any case, I hope your friend is beginning to recover from this painful condition.