Purina Pro Plan vs Hill's Science Diet: Cost & Verdict (2026)
Both vet-recommended. Both WSAVA-compliant. Both sold in clinics. Purina Pro Plan costs $10.90/kg; Hill's Science Diet costs $13.20/kg. That's $180/year more on a 70lb dog. Here's whether Hill's earns that premium.
Verdict
Purina Pro Plan is better value for most dogs. Higher protein (26% vs 20%), lower cost ($68 vs $83/month for a 70lb dog), and the most vet-funded independent feeding trial data of any brand. For healthy adult dogs, it outperforms Hill's Science Diet on protein density and cost simultaneously.
Hill's wins on one thing: its Prescription Diet therapeutic line (k/d, c/d, i/d, z/d, j/d) is genuinely superior for dogs with kidney disease, urinary issues, severe allergies, or GI conditions. Those formulas require a vet prescription for good reason â they modify nutrients outside commercial ranges to manage specific conditions. If your vet has prescribed one, that recommendation stands.
Use the dog food cost calculator to compare exact monthly costs for your dog's breed and weight on both brands.Side-by-Side Comparison
Factor Purina Pro Plan Hill's Science Diet Price per kg $10.90 $13.20 Cost per day (70lb dog) $2.27 $2.75 Monthly cost (70lb dog) $68 $83 Yearly cost (70lb dog) $816 $996 First ingredient Chicken Chicken Crude protein 26% 20% Crude fat 16% 12% WSAVA compliant Yes Yes Prescription line Yes (Purina Pro Plan Veterinary) Yes (Hill's Prescription Diet) Sensitive stomach formula Yes (Sensitive Skin & Stomach â salmon, probiotics) Yes (Sensitive Stomach & Skin) Senior formula Yes (Bright Mind â clinical EPA/DHA) Yes (Science Diet Senior) Best for Healthy adults, active dogs, sensitive stomachs Vet-directed diets, prescription therapeutic needs
The 6% protein gap (26% vs 20%) is meaningful for active dogs, working breeds, and dogs that need muscle maintenance. For a sedentary senior dog, the gap matters less. Hill's relies more heavily on whole grains as primary carbohydrate sources; Purina uses rice as a primary grain, which is easier to digest for most dogs.Ingredient Comparison
Ingredient Factor Purina Pro Plan Hill's Science Diet First 3 ingredients Chicken, rice, corn gluten meal Chicken, whole grain wheat, whole grain corn Protein sources Chicken, chicken by-product meal Chicken, chicken by-product meal Grain sources Rice, corn gluten meal Whole grain wheat, whole grain corn, sorghum Added extras Live probiotics, fish oil, glucosamine Vitamin E, fish oil, natural flavor Crude protein 26% min 20% min Omega-3 sources Fish oil (EPA/DHA) Fish oil
Hill's has sold directly to veterinarians since the 1940s â longer than Purina Pro Plan has existed. Many vets trained on Hill's prescription diets in vet school, which drives clinic stocking and familiarity. The reputation that Hill's Science Diet (OTC) carries in vet offices is largely borrowed from the Hill's Prescription Diet therapeutic line. Those are genuinely excellent medical diets. Science Diet is a separate product that benefits from the brand's vet relationships. This doesn't mean Science Diet is bad â it's a solid, WSAVA-compliant food. It means the vet recommendation for Science Diet often reflects brand trust rather than a head-to-head protein or ingredient comparison with Pro Plan.Why Vets Recommend Hill's
When Hill's Science Diet Is Worth It
When Purina Pro Plan Is the Better Choice
If your vet has recommended Hill's, confirm whether they mean Science Diet (available anywhere, no prescription) or Prescription Diet (requires vet authorization, costs $18â28/kg). They're made by the same company but are completely different products. Switching from Prescription Diet to Science Diet â or to Purina Pro Plan â may not provide the same therapeutic effect if the prescription was managing a specific medical condition. For a full breakdown: Hill's Science Diet vs Hill's Prescription Diet comparison.Important: Science Diet vs Prescription Diet
For most healthy adult dogs, no. Purina Pro Plan has higher protein (26% vs 20%), costs less ($68 vs $83/month for a 70lb dog), and has stronger independent feeding trial data. Hill's wins if your dog needs a Prescription Diet therapeutic formula for a specific medical condition. Hill's has sold directly to vets since the 1940s and many vets trained on their prescription line. The OTC Science Diet benefits from that same brand trust. It's a solid food â but the vet recommendation often reflects brand familiarity more than a direct ingredient comparison with Pro Plan. $2.30/kg less: $10.90/kg vs $13.20/kg. For a 70lb dog, that's $68 vs $83/month â $180/year saved on Purina Pro Plan. Purina Pro Plan Sensitive Skin & Stomach (salmon, rice, live probiotics) has stronger vet and feeding trial backing for digestive issues. For serious GI conditions, Hill's Prescription Diet i/d is the better therapeutic option â but that requires a vet prescription and costs $18â28/kg.Frequently Asked Questions
Is Hill's Science Diet better than Purina Pro Plan?
Why do vets recommend Hill's Science Diet?
How much cheaper is Purina Pro Plan than Hill's Science Diet?
Is Hill's Science Diet worth it for sensitive stomachs over Purina Pro Plan?
Enter your dog's breed, weight, and activity level to compare Purina Pro Plan vs Hill's Science Diet costs side by side.See Your Exact Monthly Cost on Both Brands