Last Updated: 07/09/2026
How Do You Know When It's Time to Change Your Pet's Food for Their Life Stage?
Not sure when to switch your pet's food? Our vet explains how to know when it's time to move to a new life stage diet, from puppy or kitten to senior, and how to feed them the very best nutrition at every stage.
Author: Dr Olivia Clarke BSc BVMS MANZCVS (Unusual Pets, Avian)
Reading Time: 4 minutes - short read
Puppies, kittens, adult pets and seniors all have different nutritional needs. The right food at eight weeks old isn't the right food at eight years old, and the age at which each switch should happen depends on your pet's species, breed and size.
Nutrition at each life stage plays a genuine role in supporting your pet's immune system, digestion and bone and joint health, whether they're a growing puppy or kitten building the foundations, or an older pet whose needs are starting to shift.
In this article, we'll explain why life stage matters for nutrition, why your pet's size affects the timing of each switch, and how a breeder and vet-recommended range like Royal Canin is formulated to support pets at every stage.
Why Does Life Stage Matter for Nutrition?
Puppies and kittens are growing quickly. They need higher levels of protein, energy and specific nutrient levels like calcium and phosphorus to support their developing immune system, digestion and skeletal growth. Adult pets need a more stable, maintenance level diet, while senior pets often need extra support as their metabolism, digestion, joints and immune function naturally change with age.
Feeding the wrong life stage diet too early or for too long can mean your pet misses out on the tailored nutrition they need to support their health at each stage of life.
How Do You Know When It's Time to Switch?
As a general guide, most puppies and kittens move onto an adult diet somewhere between 10 and 12 months, though larger dog breeds can take up to 24 months to finish growing. Most pets are considered senior at the age of 7 so that’s a good time to look at switching to a mature or senior diet.
For dogs, size matters a lot. Smaller breeds mature faster as puppies but age more slowly overall, while larger breeds take longer to reach adulthood but move into their senior years sooner.
That's why ROYAL CANIN(R) Mini Range, formulated for small breed dogs, moves onto an adult 8+ formula, whereas the ROYAL CANIN(R) Maxi Range has an ageing formula for large and giant dog breeds from 5+ years.
If you're ever unsure whether it's the right time for your particular pet, your vet is best placed to advise, taking into account their breed, weight and any health conditions.
How Royal Canin Supports Pets at Every Life Stage
ROYAL CANIN(R) life stage ranges are formulated with nutrient profiles that reflect what pets need at each of these stages:
- Growth (kitten and puppy): higher protein and energy levels, plus nutrients to help support a developing immune system and digestion.
- Adult maintenance: complete and balanced formulas specifically designed to meet the size, breed and health needs of pets in their adult years.
- Mature adult: an adapted formula to help support pets as their metabolism and activity levels begin to shift as they start to get older.
- Senior: nutrient adjustments to help support the immune system, digestion and joint health in ageing pets.
Why Vets and Breeders Recommend Royal Canin
Vets and breeders recommend Royal Canin because it relies on extensive scientific research, precise nutrient profiling and strict quality control. The brand formulates targeted diets for specific life stages, sizes, health concerns, and some medical conditions in collaboration with veterinary nutritionists, helping deliver predictable and reliable health outcomes.
And you can try risk free. Royal Canin backs its formulas with a palatability guarantee: your pet will love it, or your money back.
How to Switch Your Pet's Food
Whichever life stage your pet is moving to, transition gradually over 7 to 10 days by mixing increasing amounts of the new food with the old. This helps avoid tummy upset and gives your pet's gut time to adjust. Our guide to introducing a new food to your pet has a full day by day plan.
Why Life Stage Nutrition Matters
Nutrition can't change your pet's age, but it can genuinely support what their body needs at each milestone and offer real measurable differences in their health.
Matching your pet's food to their actual life stage, rather than sticking with one diet indefinitely, is one of the simplest ways to help their nutrition keep working for them at every milestone. A vet-recommended range like Royal Canin, tailored to each life stage, makes that easier to get right.
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History
Our experts continually monitor the health and wellness space and we update our articles when new information becomes available.
Mon Sep 07 2026
Written by Dr Olivia Clarke BSc BVMS MANZCVS (Unusual Pets, Avian)Dr Olivia Clarke BSc BVMS MANZCVS (Unusual Pets, Avian)
Veterinarian
Dr Olivia graduated from Murdoch University in 2015 and worked in Western Australia before moving to Sydney to work in specialist practice as an avian and exotics veterinarian. Olivia has thoroughly enjoyed the diversity of species and interesting cases in her time as an exotics veterinarian. She has a particular soft spot for rabbits and thoroughly enjoys all aspects of rabbit medicine and surgery. She also has many years of experience working with dogs and cats as well as an array of wildlife.
