Puppies and kittens grow faster, relative to their eventual adult size, than at almost any other point in their lives — and that growth isn't limited to bones and muscle. Brain development during this window sets a foundation that, in a real, measurable sense, lasts the rest of the animal's life.
What DHA actually does
DHA (docosahexaenoic acid) is an omega-3 fatty acid concentrated specifically in brain and retinal tissue — it's a structural building block, not just a general "good for you" nutrient. Nearly 60% of the brain's physical structure is made of fat, and DHA is one of the most important components of that structure. Adequate DHA intake during early development supports brain growth, and the effect on the retina means it plays a direct role in visual development too.
This isn't a small or theoretical effect. Studies feeding puppies DHA-enriched diets from weaning through their first year found measurably better results in learning, memory, and problem-solving tasks compared to puppies on standard diets. In plain terms: puppies who get adequate DHA during this window tend to learn commands faster and retain training better than puppies who don't. Kittens are, if anything, even more efficient at using DHA directly than some other species, which makes getting enough of it during this specific window particularly relevant for cats.
Beyond the brain: gut and immune development
The first year isn't only about neurological growth. The transition from mother's milk to solid food is itself a major nutritional shift, and nucleotides — building blocks the body would otherwise need to manufacture from scratch — support the digestive lining during this transition, which is part of why they're often included alongside DHA in puppy and kitten formulas. Early immune development is happening at the same time as brain development, and a young animal's system is doing a lot of work simultaneously during those first months.
DHA isn't a nutrient that matters only in puppyhood and kittenhood and then stops — it continues supporting brain and nervous system function throughout an animal's life. But the early developmental window, when the brain is being physically built, is when it matters most.
What this looks like in practice
Most puppies can start once fully weaned onto solid food, typically around 8 weeks — check with your vet if you're unsure about timing for your specific breed or litter. As your puppy approaches adulthood, generally around 12 months (later for large and giant breeds, whose growth plates don't fully close until 12–18 months), it's worth transitioning to adult-appropriate support. The same general timeline applies to kittens, who typically reach adult size and a leveled-off growth rate around the one-year mark.
Our Puppy and Kitten collections are built around this specific DHA-focused window. If you're wondering what happens nutritionally once your pet ages out of this stage, our piece on how needs shift again in the senior years picks up the story from the other end of life.
