The scores
Orijen Senior: A (90/100) — Chicken, turkey, salmon, whole herring, chicken liver. Elevated marine omega-3s, dehydrated pumpkin for digestive regularity, lentil fiber, same WholePrey base.
Orijen Original: A (90/100) — Chicken, turkey, chicken giblets, whole herring, whole hake. Standard adult maintenance tuning, functional botanicals, same animal-heavy foundation.
How the ingredients compare
Senior: Chicken, Turkey, Salmon, Whole Herring, Chicken Liver
Original: Chicken, Turkey, Chicken Giblets, Whole Herring, Whole Hake
Both lead with chicken and turkey. The senior formula elevates salmon to position three and whole herring to position four — moving marine-source omega-3s up the ingredient list, delivering richer EPA and DHA. The adult formula keeps chicken giblets in position three (organ meat blend) and uses whole hake in position five for additional marine protein diversity.
Where the Senior formula differs
Salmon and whole herring earlier in the list: Senior dogs benefit from increased omega-3 intake for two reasons. First, EPA (abundant in salmon and herring) has published anti-inflammatory effects that help manage osteoarthritic joints — studies show measurable reductions in NSAID dosing for seniors on marine-omega-3-supplemented diets. Second, DHA supports cognitive function during aging — canine cognitive dysfunction syndrome (analogous to human dementia) becomes more prevalent past age 7. The senior formula's ingredient order reflects this targeted tuning.
Dehydrated pumpkin in position #11: Pumpkin fiber is the single most vet-recommended digestive aid for senior dogs — its soluble fiber content supports stool regularity, addressing both constipation (common in less active seniors) and loose stool. Orijen's inclusion of dehydrated pumpkin as a distinct ingredient is a legitimate senior-specific addition; the adult formula includes whole pumpkin further down the list at a lower inclusion rate.
Lentil fiber: Orijen Senior adds explicit lentil fiber as a dedicated fiber source. Senior dogs with slower GI transit times benefit from added fiber for regularity. The fiber profile supports healthy fecal bulk without adding significant calories. Shop on Amazon →
Where the Original formula differs
Whole hake as a fifth animal protein: Orijen Original includes whole hake in position five, giving it five named animal proteins in the top five (chicken + turkey + chicken giblets + whole herring + whole hake). Adult dogs with higher activity levels benefit from the broader protein source diversity.
Chicken giblets rather than liver-specific: Chicken giblets (the blend of liver, heart, gizzard) provide organ meat nutritional density but with a slightly different micronutrient profile than pure liver. Both are nutritionally valuable; the blend may serve adult maintenance slightly better than the liver-focused senior formula.
Caloric density is slightly higher: Orijen Original is tuned for adult maintenance with elevated fat (around 18% vs slightly lower in Senior). Active adult dogs benefit from this density. Less active seniors may put on weight on the same portion — Orijen Senior's reduced caloric density helps owners maintain body condition without portion math. Shop on Amazon →
The bottom line
This is a life-stage decision, not a quality decision. For healthy senior dogs (7+) without kidney disease or other organ-specific conditions, Orijen Senior is the right choice — the elevated omega-3 content supports joints and cognition, and the pumpkin fiber addresses digestive regularity. For adult dogs 1–6 years old, Orijen Original is the right choice — the fifth animal protein and higher caloric density serve maintenance better. Both earn A/90 — same top-tier ingredient quality, different life-stage tuning. For seniors with diagnosed kidney disease, a vet-prescribed renal diet (Hill's k/d, Royal Canin Renal Support) is the right call instead of any Orijen formula.