Hill’s Science Diet Adult Plus Dog Food receives the Advisor’s second-lowest rating of 2.5 stars.
The Hill’s Science Diet Adult Plus product line includes the 7 dry dog foods listed below.
Each recipe includes its related AAFCO nutrient profile when available on the product’s official webpage: Growth, Maintenance, All Life Stages, Supplemental or Unspecified.
- Hill’s Science Diet Small Paws Adult 11+ [M]
- Hill’s Science Diet Small Bites Adult 7+ (2 stars) [M]
- Hill’s Science Diet Large Breed Adult 6+ (1 star) [M]
- Hill’s Science Diet Small Paws Adult 7+ (1.5 stars) [M]
- Hill’s Science Diet Youthful Vitality Small and Mini Adult 7+ (2 stars) [M]
- Hill’s Science Diet Youthful Vitality Adult 7+ Chicken and Rice (2 stars) [M]
- Hill’s Science Diet Adult 7+ Chicken Meal, Barley and Brown Rice (1.5 stars) [M]
Hill’s Science Diet Small Bites Adult 7+ was selected to represent the other products in the line for this review.
Hill's Science Diet Small Bites Adult 7+
Dry Dog Food
Estimated Dry Matter Nutrient Content
Ingredients: Chicken meal, cracked pearled barley, brown rice, whole grain wheat, whole grain corn, whole grain sorghum, whole grain oats, chicken fat, dried beet pulp, chicken liver flavor, corn gluten meal, soybean oil, lactic acid, pork flavor, potassium chloride, calcium carbonate, flaxseed, iodized salt, choline chloride, l-lysine, vitamins (vitamin E supplement, l-ascorbyl-2-polyphosphate (source of vitamin C), niacin supplement, thiamine mononitrate, vitamin A supplement, calcium pantothenate, riboflavin supplement, biotin, vitamin B12 supplement, pyridoxine hydrochloride, folic acid, vitamin D3 supplement), minerals (ferrous sulfate, zinc oxide, copper sulfate, manganous oxide, calcium iodate, sodium selenite), taurine, dl-methionine, oat fiber, l-carnitine, mixed tocopherols for freshness, natural flavors, beta-carotene, apples, broccoli, carrots, cranberries, green peas
Fiber (estimated dry matter content) = 2.5%
Red denotes controversial item
|Estimated Nutrient Content|
|Dry Matter Basis||20%||15%||57%|
|Calorie Weighted Basis||18%||32%||51%|
The first ingredient in this dog food is chicken meal. Chicken meal is considered a meat concentrate and contains nearly 300% more protein than fresh chicken.
The second ingredient is barley. Barley is a starchy carbohydrate supplying fiber and other healthy nutrients. However, aside from its energy content, this cereal grain is of only modest nutritional value to a dog.
The third ingredient is brown rice, a complex carbohydrate that (once cooked) can be fairly easy to digest. However, aside from its natural energy content, rice is of only modest nutritional value to a dog.
The fourth item is wheat. Like corn, wheat is an inexpensive and controversial cereal grain. And aside from its energy content, this grain is of only modest nutritional value to a dog.
For this reason, we do not consider wheat a preferred component in any dog food.
The fifth ingredient is corn. Corn is another cereal grain and subject to the same issues as wheat (previously discussed).
The sixth ingredient is sorghum. Sorghum (milo) is a starchy cereal grain with a nutrient profile similar to corn.
Since it is gluten-free and boasts a smoother blood sugar behavior than other grains, sorghum may be considered an acceptable non-meat ingredient.
The seventh ingredient includes oats. Oats are rich in B-vitamins, minerals and dietary fiber.
The next ingredient is chicken fat. Chicken fat is obtained from rendering chicken, a process similar to making soup in which the fat itself is skimmed from the surface of the liquid.
Chicken fat is high in linoleic acid, an omega-6 fatty acid essential for life. Although it doesn’t sound very appetizing, chicken fat is actually a quality ingredient.
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 affect the overall rating of this product.
With 7 notable exceptions…
First, this recipe contains corn gluten meal. Gluten is the rubbery residue remaining once corn has had most of its starchy carbohydrate washed out of it.
And less costly plant-based products like this can notably boost the total protein reported on the label — a factor that must be considered when judging the actual meat content of this dog food.
Next, we find beet pulp, 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.
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.
In addition, flaxseed is one of the best plant sources of healthy omega-3 fatty acids. Provided they’ve first been ground into a meal, flax seeds are also rich in soluble fiber.
However, flaxseed contains about 19% protein, a factor that must be considered when judging the actual meat content of this dog food.
We also find taurine in this recipe. Taurine is an important amino acid associated with the healthy function of heart muscle. Although taurine is not typically considered essential in canines, some dogs have been shown to be deficient in this critical nutrient.
Next, there is no mention of probiotics, friendly bacteria applied to the surface of the kibble after processing to help with digestion.
And lastly, the minerals listed here do not appear to be chelated. And that can make them more difficult to absorb. Chelated minerals are usually associated with higher quality dog foods.
Hill’s Science Diet Adult Plus
Dog Food Review
Based on its ingredients alone, Hill’s Science Diet Adult Plus looks like an average dry kibble.
But ingredient quality by itself cannot tell the whole story. We still need to estimate this Science Diet product line’s meat content before determining a final rating.
As a group, the brand features an average protein content of 21% and a mean fat level of 14%. Together, these figures suggest a carbohydrate content of 57% for the overall product line.
And a fat-to-protein ratio of about 69%.
Which means this Science Diet product line contains…
Below-average protein. Below-average fat. And above-average carbs when compared to other dry dog foods.
When you consider the protein-boosting effect of the corn gluten meal and flaxseed in this recipe, and the soybean meal contained in some others, this looks like the profile of a kibble containing a limited amount of meat.
However, with 32% of the total calories in our example coming from fat versus just 18% from protein, some recipes may not be suitable for every animal.
Hill’s Science Diet Adult Plus is a grain-inclusive dry dog food using only a limited amount of named meat meal as its main source of animal protein, thus earning the brand 2.5 stars.
Hill’s Science Diet
The following list (if present) includes all dog food recalls since 2009 directly related to Science Diet. If there are no recalls listed in this section, we have not yet reported any events.
- Hill’s Prescription Diet and Science Diet Dog Food Recall Expands to Include 44 Varieties (3/20/2019)
- Hill’s Prescription Diet and Science Diet Dog Food Recall (1/31/2019)
- Hill’s Science Diet Dog Food Market Withdrawal of November 2015 (11/29/2015)
- Hill’s Science Diet Dog Food Recall June 2014 (6/3/2014)
A Final Word
The Dog Food Advisor is privately owned. We do not accept money, gifts, samples or other incentives in exchange for special consideration in preparing our reviews.
However, we do receive a referral fee from online retailers (like Chewy or Amazon) when readers click over to their website from ours. This policy helps support the operation of our blog and keeps access to all our content free to the public.
For more information, please visit our Disclaimer and Disclosure page.
Important FDA Alert
The FDA is investigating a potential link between diet and heart disease in dogs. Click here for details.
Notes and Updates
10/05/2019 Last Update