The scores
Wellness CORE Cat: A (90/100) — Clears the A threshold. Four named animal proteins in the first four positions, grain-free with legumes, multi-strain probiotics.
Nulo Cat: B (88/100) — Near the top of B grade. Chicken-focused formula with salmon oil at position five, BC30 probiotic, chicory root prebiotic.
CORE clears the A-grade threshold of 90 by a whisker, while Nulo sits at B/88 — just 2 points below. Both formulas get the fundamentals right: named animal proteins first, no fillers in the top positions, no artificial preservatives, and thoughtful additions like probiotics for digestive health. The 2-point gap comes down to CORE’s unusually protein-dense opening.
How the ingredients compare
Here are the first five ingredients side by side:
Wellness CORE: Deboned Turkey, Deboned Chicken, Turkey Meal, Chicken Meal, Peas
Nulo: Deboned Chicken, Chicken Meal, Peas, Sweet Potatoes, Salmon Oil
The difference is immediately visible. Wellness CORE dedicates its entire top four to animal proteins — two whole meats and two concentrated meals from two different poultry species. The first plant ingredient (peas) doesn’t appear until position five. That’s an exceptionally protein-dense opening for a dry cat food.
Nulo takes a different approach. It leads with deboned chicken and chicken meal (two strong animal proteins), then shifts to plant-based carbohydrate sources at positions three and four (peas and sweet potatoes). But here’s where it gets interesting: position five is salmon oil, not another filler or carbohydrate. Having a named omega-3 source this high in the ingredient list is unusual and meaningful — most foods bury their fish oils much further down where the amounts are negligible.
Both formulas are grain-free, relying on legumes (peas, lentils) and potatoes for their carbohydrate structure. Neither uses corn, wheat, or soy anywhere in the formula. For cats — obligate carnivores who have limited ability to digest plant starches — this is exactly the kind of approach that earns a high score.
Where Wellness CORE pulls ahead
Protein diversity: Wellness CORE’s biggest strength is the sheer variety of its animal protein sources. The top four ingredients alone span two species (turkey and chicken) in both whole and meal form. Further down the ingredient list, you’ll find herring meal, adding a third species. This multi-species approach provides a broader amino acid profile and reduces the risk of developing a protein sensitivity from overexposure to a single source — a real concern for cats fed the same protein for years.
Four animal proteins before any plant ingredient: Having animal protein at positions one through four is rare in dry cat food. Most premium brands manage two, maybe three animal proteins in the top five. Wellness CORE’s formula reads more like a wet food ingredient list, which is a significant achievement for a kibble. The protein meals (turkey meal and chicken meal) are particularly valuable because the rendering process removes water, concentrating the protein to roughly 3x the density of the whole meats.
Multi-strain probiotics: Wellness CORE includes multiple probiotic strains rather than relying on a single one. A multi-strain approach can support a broader range of gut health benefits, including improved digestion, better nutrient absorption, and a stronger immune response. Gut health is especially important for cats, whose digestive systems are highly specialized for processing animal proteins. Shop on Amazon →
Where Nulo holds its own
Salmon oil at position five: This is Nulo’s signature advantage. Salmon oil is one of the richest sources of EPA and DHA omega-3 fatty acids, which support skin health, coat quality, joint function, and brain health in cats. Having it at position five — well above the typical placement in most cat foods — means your cat is getting a meaningful dose, not just a trace amount for marketing purposes.
BC30 probiotic: Nulo uses Bacillus coagulans (GanedenBC30), a spore-forming probiotic that’s exceptionally stable through the manufacturing process. Many probiotics added to kibble don’t survive the extrusion heat. BC30 is designed to remain viable until it reaches your cat’s gut, making it one of the more effective probiotic inclusions in dry pet food.
Chicory root prebiotic: In addition to the BC30 probiotic, Nulo includes chicory root extract, which is a natural source of inulin — a prebiotic fiber that feeds beneficial gut bacteria. The probiotic-prebiotic combination (often called a synbiotic) creates a more complete digestive support system than either component alone.
Sweet potatoes as a carbohydrate source: While both foods use peas, Nulo adds sweet potatoes at position four. Sweet potatoes are a nutrient-dense carbohydrate source with a lower glycemic index than white potatoes, and they provide beta-carotene, fiber, and several B vitamins. As a carbohydrate choice for a grain-free formula, sweet potatoes are about as good as it gets. Shop on Amazon →
The bottom line
Wellness CORE edges Nulo 90 to 88, earning the A grade. Choosing between them comes down to what you value most. If protein diversity and sheer animal-protein density matter most, Wellness CORE’s four-animal-protein opening clears A-grade nutrition. If you prioritize omega-3 delivery, probiotic survivability, and a synbiotic digestive approach, Nulo’s formula is thoughtfully engineered for those outcomes — and 2 points below the A line hardly means a downgrade.
Either way, your cat is eating better than roughly 90% of the commercial cat food market. The only food in our database that outscores CORE is Orijen Cat at A/91 — just 1 point higher. At this tier, you’re splitting hairs between excellent options.
Read our full reviews of Wellness CORE Cat and Nulo Cat for the complete ingredient breakdowns.