The scores
Nulo Freestyle Puppy Turkey & Sweet Potato: A (90/100) — Deboned turkey, turkey meal, salmon meal, chickpeas, chicken fat. BC30 probiotic, salmon oil DHA, functional vegetables and fruits.
Nulo Freestyle Adult Salmon & Peas: A (90/100) — Deboned salmon, salmon meal, whole dried egg, turkey meal, menhaden fish meal. Three marine-protein sources, whole egg for amino acid completeness.
How the ingredients compare
Puppy: Deboned Turkey, Turkey Meal, Salmon Meal, Chickpeas, Chicken Fat
Adult Salmon: Deboned Salmon, Salmon Meal, Whole Dried Egg, Turkey Meal, Menhaden Fish Meal
The puppy formula leads with turkey — a lighter, more digestible protein source that's typically well-tolerated by young digestive systems. Turkey meal (position #2) concentrates the poultry protein. Salmon meal (position #3) adds marine-source omega-3s. The adult salmon formula, by contrast, doubles down on salmon and marine protein — deboned salmon + salmon meal + menhaden fish meal. Whole dried egg at position three is a premium protein source with biological value near 100. Both formulas include turkey meal and both deliver concentrated animal protein density.
Where the Puppy formula differs
Turkey-forward formulation: Turkey is one of the most hypoallergenic mainstream animal proteins — lower allergic-reaction incidence than chicken or beef. For puppies with unknown food sensitivities, a turkey-first formula is a sensible starting point, reducing the chance of an early elimination-diet challenge.
Chickpeas + sweet potato for puppy-friendly carbs: The low-glycemic-index carbohydrate stack (chickpeas, sweet potato, yellow peas) delivers sustained energy without rapid blood sugar spikes. For growing puppies whose insulin sensitivity is being established during the first 12 months, a low-GI carb base may support better metabolic foundation.
Functional vegetables and fruits: Dried tomatoes, dried carrots, dried blueberries, dried apples add polyphenols and antioxidants. Micronutrient-range contributions, but they signal formulation intent and contribute to overall nutrient diversity. The adult salmon formula uses a simpler ingredient list by comparison. Shop on Amazon →
Where the Adult Salmon formula differs
Triple marine-protein stack: Deboned salmon + salmon meal + menhaden fish meal gives the adult formula three marine protein sources in the top five. For adult dogs benefiting from concentrated marine-source EPA and DHA (skin and coat support, anti-inflammatory effects, cognitive maintenance), this density is stronger than the puppy formula's single marine source (salmon meal at position #3).
Whole dried egg in position #3: Whole egg is one of the highest biological value protein sources in food science (essentially the gold standard). The adult formula includes it in the top three, which is unusual and a quality signal. The puppy formula lacks this particular protein addition at the same inclusion rate.
Simpler ingredient list: The adult salmon formula has a tighter, more focused ingredient panel with fewer vegetables and fruits. For adult dogs already through the microbiome establishment phase, the functional plant diversity is less critical than raw protein quality. Shop on Amazon →
When to switch: the decision tree owners actually need
"Switch at 12 months" is the shorthand most owners remember, but it's not how the transition actually works. The correct trigger is growth-plate closure, and growth plates close at different ages across breed sizes. For a small-breed Nulo feeder (projected adult weight under 25 lb), growth plates typically close at 9–11 months — transition window opens at 10 months. For medium breeds (25–50 lb), closure lands at 12–16 months, so the transition window opens around 13 months. Large breeds (50–90 lb) close at 16–20 months; giant breeds (90+ lb) close at 20–24 months. Transitioning to Nulo adult before skeletal maturity under-supplies the targeted calcium and phosphorus doses of the puppy formula during the final phase of bone densification, with documented orthopedic consequences.
Body condition score (BCS) is the other critical input. On the 9-point BCS scale, a transitioning puppy should be at 4–5 (ribs palpable with minimal fat cover, visible waist). A BCS of 6+ means the puppy is overnourishing on the current portion — the transition should be paired with a portion reduction, not an ingredient swap. A BCS of 3 means under-feeding — transitioning to a lower-calorie adult formula will exacerbate the problem. Take BCS measurements weekly during months 9–16; the transition decision is a two-variable function of age and BCS, not calendar alone.
The transition protocol itself should run 7–10 days: days 1–3 at 75% puppy / 25% adult, days 4–6 at 50/50, days 7–9 at 25/75, day 10+ at 100% adult. Faster transitions produce GI upset in roughly 20–30% of puppies (loose stool, soft formed stool, or occasional vomiting); slower transitions are fine but not necessary. For puppies with documented GI sensitivity, stretch the transition to 14 days and add a canine probiotic during the shift.
Caloric density differs meaningfully between the Puppy and Adult Salmon formulas. Nulo Puppy runs approximately 445 kcal/cup; Nulo Freestyle Adult Salmon runs approximately 415 kcal/cup — a ~7% reduction at equal volume. For a 40-lb dog eating 2 cups/day, that's a 60 kcal/day reduction — appropriate for the lower metabolic rate of adult maintenance. Portions should be recalibrated at the transition: if the puppy was eating 2 cups of puppy food, the transitioned adult may need 2 cups of adult food (slightly fewer calories) or slightly less depending on body condition, not more.
Grain-free and legume-forward formulas like Nulo's deserve an extra conversation at the life-stage transition. The FDA's ongoing diet-associated DCM investigation has a statistical signal in adult dogs specifically; puppies on grain-free formulas haven't shown the same epidemiological pattern, but cumulative exposure matters. For DCM-susceptible breeds (Golden Retrievers, Labrador Retrievers, Doberman Pinschers, Boxers, Great Danes, Cocker Spaniels, Newfoundlands), the transition from Nulo Puppy to Nulo Adult is the natural moment to discuss continuing grain-free vs adding a grain-inclusive option with the vet. Many vets recommend rotating to a grain-inclusive formula for DCM-susceptibles at the adult transition; others are comfortable continuing Nulo's grain-free line with periodic echocardiograms. Either path is defensible with vet involvement.
Feeding frequency also shifts. Puppies on Nulo Puppy typically eat 3 meals per day through 6 months, then 2 meals per day through the transition. Adult dogs on Nulo Adult do well on 2 meals per day — twice-daily feeding is better than once-daily for GI health, insulin response, and behavioral management. If transitioning from a 3-meal to 2-meal schedule, combine meals 1+2 or reduce one meal portion progressively over 3–5 days.
The bottom line
This is a life-stage decision. For puppies under 12 months, Nulo Puppy is the right choice — the turkey-forward formulation, low-GI chickpea/sweet potato carb base, and puppy-tuned calcium and fat levels align with growth-stage requirements. For adult dogs 12+ months, Nulo Freestyle Adult Salmon & Peas (or any of Nulo's adult variants) is the right choice — the triple marine protein stack and whole egg addition optimize for maintenance nutrition. Both earn A/90 — same top-tier ingredient quality, different life-stage tuning. Large-breed puppy owners should verify calcium levels with their vet. DCM-susceptible breed owners (goldens, cockers, Dobermans, Great Danes) should discuss grain-free formulas with their vet before long-term commitment.