The scores
Blue Buffalo Life Protection: B (78/100) — Above average. Two named animal proteins lead the formula, backed by quality whole grains.
Purina Pro Plan: C (62/100) — Average. Chicken is first, but by-product meal and soybean meal fill in behind it.
How the ingredients compare
The top five ingredients tell the story:
Blue Buffalo: Deboned Chicken, Chicken Meal, Brown Rice, Oatmeal, Barley
Purina Pro Plan: Chicken, Rice, Poultry By-Product Meal, Soybean Meal, Corn Protein Meal
Blue Buffalo has two named animal protein sources before any carbohydrate. Purina Pro Plan has one named protein, then rice, then three ingredients that are either by-products or plant-based protein boosters. That's a fundamental difference in formula philosophy.
The grain quality is also a clear gap. Blue Buffalo uses brown rice, oatmeal, and barley — whole grains with fiber, B vitamins, and slow-release energy. Purina Pro Plan uses rice (likely white rice, lower in nutrients), soybean meal (a cheap plant protein), and corn protein meal (another plant protein filler). Pro Plan is leaning hard on plant proteins to get its guaranteed analysis numbers up.
Where Blue Buffalo pulls ahead
Protein sourcing: Having both deboned chicken and chicken meal in the top two positions means more of the protein in Blue Buffalo is actually coming from animal sources. Chicken meal is roughly 3x more concentrated in protein than whole chicken since the water is already removed. Purina Pro Plan's poultry by-product meal is a lower-quality protein source — it includes heads, feet, and organs, and the generic "poultry" label means it can come from any bird species.
Grain quality: Brown rice, oatmeal, and barley are meaningfully better carbohydrate sources than the rice-soybean-corn combination in Pro Plan. They digest slower, provide more nutrients, and aren't just there to fill the bag cheaply.
No plant-protein padding: While Blue Buffalo does use some pea protein further down its ingredient list, it doesn't rely on soybean meal and corn protein meal as primary ingredients the way Pro Plan does. Shop on Amazon →
Where Purina Pro Plan holds its own
Pro Plan has two things going for it. First, it's one of the most widely recommended brands by veterinarians. Purina funds a large amount of veterinary nutrition research, and many vets are comfortable with the brand's feeding trial history. That's worth something, even if the ingredient list isn't impressive.
Second, Pro Plan has an enormous product line with specialized formulas for specific needs — sensitive skin, weight management, sport performance, large breed, small breed. If your dog has a particular dietary need, Pro Plan probably has a formula for it. Blue Buffalo's lineup is more limited.
Pro Plan also tends to be slightly cheaper per pound than Blue Buffalo, though the gap isn't as large as you might expect. Shop on Amazon →
The bottom line
If you're choosing between these two, Blue Buffalo Life Protection is the better food by our ingredient analysis — and it's not close. A 16-point gap across one full letter grade reflects real differences in protein quality and carbohydrate sourcing. Pro Plan isn't bad food, but it relies too heavily on by-products and plant proteins to compete with Blue Buffalo's cleaner formula.
That said, if your dog is doing well on Pro Plan and your vet recommends it for a specific reason, that's a valid consideration. But if you're just grabbing a bag off the shelf and comparing labels, Blue Buffalo is the stronger choice. Read our full reviews of Blue Buffalo and Purina Pro Plan for the complete breakdown.