The scores
Diamond Naturals Small & Medium Breed Puppy Chicken & Rice: B (78/100) — Chicken, chicken meal, white rice, chicken fat, cracked pearled barley. Salmon oil for DHA, five-strain probiotics, functional vegetables (kale, pumpkin, blueberries).
Diamond Naturals Adult Chicken & Rice: B (78/100) — Chicken, chicken meal, whole grain brown rice, cracked pearled barley, white rice. Glucosamine HCl, chondroitin sulfate, five-strain probiotics.
How the ingredients compare
Puppy: Chicken, Chicken Meal, White Rice, Chicken Fat, Cracked Pearled Barley
Adult: Chicken, Chicken Meal, Whole Grain Brown Rice, Cracked Pearled Barley, White Rice
Identical first two ingredients: chicken and chicken meal. From position three the formulas diverge: the puppy formula uses white rice (more digestible, lower fiber — easier on developing GI tracts), while the adult formula uses whole grain brown rice (higher fiber, more complex carbohydrate profile). Chicken fat moves up to position four in the puppy formula (reflecting higher caloric needs during growth), while the adult formula saves it for position six or later. Both formulas include cracked pearled barley as a secondary grain.
Where the Puppy formula differs
Salmon oil as a dedicated DHA source: The puppy formula explicitly lists salmon oil as a source of DHA. Puppies need DHA during the first 12 months for brain, eye, and nervous system development, and salmon oil is one of the most bioavailable delivery mechanisms. The adult formula uses salmon oil but does not specifically call out the DHA labeling — reflecting the lower relative need for the nutrient in adult maintenance.
White rice as primary carb: White rice has a higher glycemic index than brown rice but is significantly more digestible, particularly for puppies whose GI tracts are still maturing. Many puppies transition more smoothly onto white rice, making this a formulation choice optimized for puppy comfort rather than fiber maximization.
Functional vegetables and fruits in greater variety: Kale, chia seed, pumpkin, blueberries, oranges, quinoa, coconut, spinach, carrots, papaya. The adult formula uses a subset of these additions. For puppy microbiome development and antioxidant support during growth, the broader diversity contributes real nutritional value.
Higher fat percentage: Growing puppies need denser caloric content. The puppy formula runs roughly 22% fat vs the adult formula's ~16%. This is a life-stage tuning optimized for metabolic demand during weight gain. Shop on Amazon →
Where the Adult formula differs
Glucosamine HCl and chondroitin sulfate supplementation: The adult formula explicitly adds dedicated glucosamine and chondroitin for joint support. These ingredients become increasingly valuable as dogs age and begin experiencing early-stage osteoarthritis. The puppy formula relies on natural connective-tissue content from meat ingredients rather than supplementation — appropriate for dogs still building joint structure rather than maintaining it.
Whole grain brown rice: The adult formula uses whole grain brown rice as its primary carb source. Brown rice carries more fiber, B vitamins, and minerals than white rice — a nutritionally denser starch source appropriate for adult dogs with mature digestive capacity. For adult maintenance nutrition, brown rice is the stronger choice.
Higher fiber profile overall: Between whole grain brown rice, cracked pearled barley, and dried beet pulp, the adult formula runs a higher fiber profile. This supports stable stool quality, healthy gut transit times, and long-term digestive regularity for adult dogs. Shop on Amazon →
The bottom line
This is a life-stage decision — both formulas deliver B/78 ingredient quality within the Diamond Naturals brand. For puppies under 12 months (small and medium breeds under 50 lb projected adult weight), Diamond Naturals Small & Medium Breed Puppy is the right choice — salmon oil DHA, white rice digestibility, and higher fat content align with growth-stage requirements. For adult dogs 12+ months, Diamond Naturals Adult Chicken & Rice is the right choice — the glucosamine/chondroitin supplementation and brown rice fiber profile better serve adult maintenance. Large-breed (50+ lb) and giant-breed (90+ lb) puppies should use the dedicated Diamond Naturals Large Breed Puppy variant instead — the calcium and joint-support tuning differs. Both puppy and adult formulas deliver strong value at roughly 30–40% below premium competitors.