Hill's Science Diet vs Purina Pro Plan: Which Adult Dog Food Is Better?
Hill's Science Diet Adult 1-6 Chicken & Barley Recipe Dry Dog Food
Full review →Purina Pro Plan Complete Essentials Adult Shredded Blend Chicken & Rice Formula
Full review →The short answer. Hill's wins by four points, and the deciding factor is transparency rather than nutrition: 80 against 62. Purina's label relies on by-product meals and soy, which it does not disclose in the detail Hill's does. Purina fights back with more protein, a lower price per pound and 14,599 owner ratings.
Side by side
Every number below comes from the manufacturer's current label or current US retail listings, scored on the same 6-dimension model. Shaded cells mark the better value on that row.
| Attribute | Hill's Science Diet Adult 1-6 Chicken & Barley Recipe Dry Dog Food | Purina Pro Plan Complete Essentials Adult Shredded Blend Chicken & Rice Formula |
|---|---|---|
| Overall score | 84 / 100 | 80 / 100 |
| Protein quality & source (30%) | 78 | 74 |
| Ingredient transparency (20%) | 80 | 62 |
| Nutritional standards (18%) | 92 | 90 |
| Recall history & safety (14%) | 80 | 84 |
| Value for money (10%) | 97 | 100 |
| Owner & pal feedback (8%) | 94 | 92 |
| Protein (as fed) | 20.0% | 26.0% |
| Protein (dry matter) | 22.2% | 29.5% |
| Fat (min) | 11.5% | 16.0% |
| Fibre (max) | 4.0% | 3.0% |
| Moisture | 10.0% | 12.0% |
| Calorie density | 3,675 kcal/kg | 4,038 kcal/kg |
| Price per lb | $2.49/lb | $2.13/lb |
| Price per 1,000 kcal | $1.49 | $1.16 |
| Owner rating | 4.7/5 (4,697 ratings) | 4.6/5 (14,599 ratings) |
| First ingredient | Chicken | Chicken |
| Form | Dry (kibble) | Dry (kibble) |
| Life stage | Adult maintenance | Adult maintenance |
| Best for | Average adult dogs, and owners who want the option their vet is most likely to endorse | Adult dogs of any size on a budget, and picky eaters that respond to mixed textures |
Where the difference actually comes from
These two are the foods a vet is most likely to name, and they split the decision differently than buyers expect. Hill's Science Diet Adult sits at 20% protein; Purina Pro Plan Savor is at 26%. If you shop on the guaranteed analysis alone, Purina looks like the better food. It is not what our scoring says, because protein percentage is only one of six weighted dimensions.
Transparency is the real separator. Hill's publishes a full ingredient rationale and participates in feeding-trial-grade research, scoring 80 on transparency and 92 on standards. Purina's 62 on transparency reflects an ingredient panel built on chicken by-product meal, corn gluten and soy, with less published detail behind it. Its standards score of 90 is strong — this is not an unsafe food — but the label tells you less.
Purina's value score of 100 is the highest in this comparison and it holds a 4.6/5 across 14,599 ratings, which is the largest review sample of any dry dog food here. At $2.13/lb against Hill's $2.49/lb, it is also the cheaper feed. For picky eaters the shredded-blend texture is a genuine advantage.
Which one should you buy?
Choose Hill's Pet Nutrition if
You want the option your vet is most likely to endorse, full ingredient disclosure, and a food formulated conservatively for an average adult dog.
Choose Purina Pro Plan if
You want more protein for less money, you have a picky eater who responds to mixed kibble textures, or you are feeding a large dog on a budget.
Pros and trade-offs
Hill's Pet Nutrition
What owners and our testing liked
- Feeding-trial validated, not just formulated to meet profiles - the strongest adequacy evidence in this category
- 4.7/5 across roughly 4,700 Chewy ratings and the most consistently vet-recommended food here
- About $1.49 per 1,000 kcal from a 35 lb bag, which is genuinely cheap for a research-backed formula
- Moderate 20% protein and 11.5% fat suits the average adult dog better than a 38% performance food
Trade-offs
- Brewers rice, corn protein meal and soybean meal sit in the first eight ingredients
- 20% protein is unremarkable on paper - the DMB figure is about 22%, below this ranking's average
- The 2019 vitamin D recall was the largest of its kind in US pet food history, even though it did not touch dry food
Purina Pro Plan
What owners and our testing liked
- Feeding-trial validated and made in Purina-owned US plants, with roughly 400 scientists behind the line
- About $1.16 per 1,000 kcal - the cheapest food in this ranking per calorie
- 4.6/5 across roughly 14,600 Chewy ratings, and the dual kibble-and-shred texture wins over most picky eaters
- Real chicken first, with rice and whole grain wheat rather than a legume-heavy base
Trade-offs
- Poultry by-product meal and soybean meal both appear in the top five
- 12% moisture is higher than most dry foods, so you are paying for a little water
- 26% protein is respectable but not high; working dogs will want more
Frequently asked questions
Why does Purina Pro Plan score lower if it has more protein?
Because protein percentage is one of six weighted dimensions, at 30% of the total. Purina also scores 62 on ingredient transparency against Hill's 80, which reflects the use of by-product meals and soy with less published detail. The higher protein is real; it simply does not outweigh the other five dimensions.
Is chicken by-product meal a problem?
It is not a safety problem — by-product meal is a rendered, protein-dense ingredient that is nutritionally usable. The objection is transparency: it is an unnamed source, so you cannot tell what proportion came from which part of the animal. That uncertainty is what the transparency score penalises.
Which is better for a large breed?
Both carry adult-maintenance AAFCO statements and both are fed widely to large dogs. Purina Pro Plan Savor is more calorie-dense at 4,038 kcal/kg versus 3,675, so portions are smaller. For large-breed puppies specifically you need a growth formula, not either of these adult foods.
Want to compare more than two? Use the comparison tool — up to four foods side by side. Individual animals vary; if your pet has a diagnosed condition, confirm the choice with your veterinarian.