Last Updated: 07/10/2026
Age Appropriate Food
Wondering if you are feeding an age appropriate diet to your pet? Find out more about what their age means for your pets health and how nutrition can help.
Author: Dr Belinda Stancombe BVSc (Hons)
Reading Time: 7 minutes - short read
Ever wondered if your pet is getting the right food for their age? Gone are the days of 'one size fits all' pet food. Diets are now formulated for growing pets, adults, mature and senior pets, and there are even therapeutic diets that help treat conditions like obesity, arthritis, and renal, urinary and liver disease.
The right food depends on your pet's lifestage. Puppies and kittens need a growth diet until they reach full size (anywhere from 7 to 24 months, depending on breed), adults need a maintenance diet, and mature and senior pets do best on diets that manage age-related risks like weight gain, arthritis and kidney disease.
Not sure which lifestage your pet is in? Start with their age below. We've also covered how old that really is in human years.
What should I feed my puppy or kitten?
Puppies and kittens need a growth diet, labelled for 'puppy' or 'kitten', until they reach their full size. They need more protein, fat, energy, calcium and phosphorus than adults, but the goal is optimal growth, not maximum growth. Too little food can lead to malnourishment, and too much can lead to skeletal abnormalities and obesity later in life.
This means you should focus less on breed standard expectations and more on your puppy or kitten's body condition score (BCS). Check their BCS and weight weekly until they're 6 months old. Our guide on How to Assess Your Pet's Body Condition Score has tips, or ask your vet.
For puppies, many premium brands have food categories based on predicted adult weight: Small or Toy (under 10kg), Medium (10 to 25kg), Large (25 to 40kg) and Giant (over 40kg). This is especially important for large and giant breeds, whose diets have controlled calcium and phosphorus and are energy dense to promote optimal growth and help decrease orthopaedic conditions.
Luckily, you don't need to worry about the science. Most foods labelled 'puppy' or 'kitten' are already balanced with the right ingredients.
TIP: To check a food is complete and balanced for your pet's lifestage, look for an AAFCO statement on the packaging.
How long does my pet need to stay on puppy or kitten food?
Typically, pets reach their full growth around the following ages:
- Cats: 7-12 months
- Large Breed Cats: 12-15 months
- Small Breed Dogs: 7-12 months
- Medium Breed Dogs: 10-12 months
- Large Breed Dogs: 15-18 months
- Giant Breed Dogs: 18-24 months
* keep in mind that these are only guidelines. The best way to know whether your pet needs to transition to a less calorie-dense adult food is by assessing its body condition.
After more information or the best diet for your pet? See our article Best Puppy Food or Best Kitten Food. Or for the bigger picture on choosing food across your dog's whole life, see our Dog Food Buying Guide. Feeding a cat instead? Our guide to choosing the right nutrition for your cat covers the same ground for kittens through to senior cats.
What should I feed my adult dog or cat?
Once your puppy or kitten is fully grown, switch to a diet labelled for 'adults'. Adult diets have fewer calories and less protein, fat, calcium and phosphorus than puppy or kitten food. Apart from dental disease and obesity, this is typically a healthy period in a dog or cat's life.
Hopefully these years go by without much need for a major diet change! You might like to feed a dental food for teeth maintenance, or a diet to support skin and coat or a sensitive tummy. Breed-specific diets are another option if you'd like to focus on your pet's exact needs, with popular ones including Golden Retriever, Pug, Ragdoll and Persian.
Still not sure what to choose? Read this helpful guide: Premium Pet Food: Is It Worth It?, and our guide to How to Choose the Best Food for Your Dog's Breed.
When should I switch to a mature adult diet?
Most pets move to a mature adult diet between 5 and 8 years of age, depending on their size. Nutritional requirements are very similar between adult and 'mature' adult, so the change is about managing risk. Certain diseases start to develop around this age, so by adjusting the diet, for example by decreasing caloric intake by 20 to 30% while still meeting essential nutritional needs, we can help to slow the ageing process and reduce the risk of cancer, renal disease, arthritis and immune-mediated disease.
The right age depends on your individual pet. Overweight pets, and even dogs with bad teeth, age a lot quicker than healthy, fit pets, and large breeds become senior much sooner than small breeds. Cats are extremely variable, with their 'mature' stage emerging anywhere between 7 and 12 years.
Typically, the age at which a pet is considered 'mature adult' is as follows:
- Cats: 7 years old
- Small Breed Dogs: 8 years old
- Medium Breed Dogs: 7 years old
- Large and Giant Breed Dogs: 5-6 years old
What should I feed a senior or geriatric pet?
Senior pets do best on a diet that supports age-related changes. Thanks to vast improvements in pet healthcare and nutrition, pets are living longer than ever, and these twilight years tend to bring the most problems with arthritis, certain cancers, immune-mediated disease, thyroid issues and renal disease.
For their golden years, a few super premium brands make a special 'age-defying' or 'ageing' food for this extra-senior age range. These foods have nutrients adjusted to support kidney function, immunity, joints (with added chondroitin and glucosamine) and brain function (with added EPA, DHA and antioxidants), and some even have a softer kibble to encourage geriatric pets to eat more.
Typically, the age at which a pet is considered 'senior' or 'geriatric' is as follows:
- Cats: 11-12 years old
- Small Breed Dogs: 11-12 years old
- Medium Breed Dogs: 10 years old
- Large and Giant Breed Dogs: 8 years old
How old is my pet in human years?
Not as old as the old "multiply by 7" rule suggests. That shortcut doesn't hold up, pets age fastest in their first two years, then slow down, and how quickly they slow down depends heavily on their size. Here's a quick snapshot:
Small breed dogs and cats (age slowest after maturity):
- 1 year old = around 15 human years
- 5 years old = around 36 human years
- 10 years old = around 56 human years
- 15 years old = around 76 human years
Medium breed dogs:
- 1 year old = around 15 human years
- 5 years old = around 37 human years
- 10 years old = around 60 human years
Large breed dogs (age fastest, senior status arrives earlier):
- 1 year old = around 14 human years
- 5 years old = around 40 human years
- 8 years old (senior) = around 55 human years
These figures are approximations and individual variation is significant.
In the vet consult room. the number on a chart matters less than what we're actually seeing in front of us. Two 10 year old Labradors can have very different "true ages" depending on weight and joint health, we look at dental wear, joint mobility, coat condition and muscle tone together, not just the birthdate on file.
Are 'all life stages' diets okay for my pet?
Yes, they can be, as long as you follow the feeding guidelines. An 'all life stages' food is balanced for growth and reproduction (puppies, kittens and pregnant animals), so it's most suitable for them, but it's in line with AAFCO guidelines and deemed fine for adult and senior pets too.
To suit growth and reproduction, these foods are higher in calories, protein and fat, with a specific calcium and phosphorus balance. The main risk for adults is weight gain, and it's even higher for seniors, who tend to have a slower metabolism and may not need such high levels of these nutrients.
An 'all life stages' food might be perfect for multi-pet households where you'd like to feed the same food to animals of different ages. It can also suit a puppy reaching adulthood whose owner would rather not change foods. For households with only adult dogs, or especially only senior dogs, we generally recommend a food designed for their needs.
In summary, the food you choose should depend on your pet's individual development. Keep a close eye on their weight and feed an age and breed appropriate food, and you can help give your pet the best chance at a long and happy life.
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History
Our experts continually monitor the health and wellness space and we update our articles when new information becomes available.
Thu 8 Oct 2026
Edited by Dr Gillian Hill BVSc (Hons)Dr Belinda Stancombe BVSc (Hons)
Veterinarian
Dr Belinda graduated from The University of Queensland in 2009 and has worked as a Small Animal Veterinarian for over 10 years in South East Queensland. She also has experience as a telehealh consultant, providing veterinary advice for online customers.She has a special interest in animal behaviour, preventative health, the human-animal bond and internal medicine. Outside of work hours she is closely affiliated with a kitten rescue and is also a devoted carer of orphaned rescue kittens.
