---
title: "Senior Dog Food UK: When to Switch & What to Look For | Dog Years"
description: "When to switch a UK dog onto senior food, by size. What complete and complementary labels mean, and how calories, protein and wet food differ."
image: "https://dogyears.info/result-image.png?t=Senior%20Dog%20Food%20UK%3A%20When%20to%20Switch%20%26%20What%20to%20Look%20For&s=When%20to%20switch%2C%20by%20size"
url: "https://dogyears.info/senior-dog-food-uk"
---

# Senior Dog Food UK: When to Switch & What to Look For

Switch by your dog's size, then read the label. "Senior" is not a league table.

This is general information for UK owners, not a veterinary diet and not a ranking of brands or prices. The ages below are the same Royal Kennel Club size bands this site already uses, as tabulated by Purina UK. Check a named breed or a birthday on the [calculator](https://dogyears.info/), or the whole-year figures on the [age chart](https://dogyears.info/#age-chart).

## When to switch to senior dog food, by size

On this site, a senior dog diet starts when the dog reaches the senior year for their adult weight. That is a care guideline for when to look again at food, walks and vet checks. It is not a switch that flips on the birthday. [Signs your dog is a senior](https://dogyears.info/signs-your-dog-is-a-senior) is what the change looks like at home. [Dog life stages](https://dogyears.info/dog-life-stages-explained) and [small versus large breed ageing](https://dogyears.info/small-vs-large-breed-ageing) set the bands out in full.

| Size | Adult weight | Senior from | Human years then |
| --- | --- | --- | --- |
| Small | Under 9 kg | 10 years | 56 |
| Medium | 9–23 kg | 7 years | 47 |
| Large | 23–41 kg | 5 years | 36 |
| Giant | Over 41 kg | 5 years, sometimes earlier | 45 at 5 years |

Source: The Royal Kennel Club's dog-years-to-human-years guidance, as published via Purina UK. These are the same whole-year figures as the [calculator](https://dogyears.info/) and the [homepage chart](https://dogyears.info/#age-chart). Small dogs are generally treated as senior from 10, medium dogs from 7, and large dogs from 5. Giant dogs use that same 5-year mark in the calculator. The [size guide](https://dogyears.info/small-vs-large-breed-ageing) also says giant dogs are sometimes treated as senior earlier than 5. This site does not publish a separate earlier number, so use 5 unless your vet has a reason to look sooner for that dog.

By 10 dog years every band on the chart is already senior. Later birthdays, with the human-year range for each one, are [10](https://dogyears.info/10-dog-years-in-human-years), [11](https://dogyears.info/11-dog-years-in-human-years), [12](https://dogyears.info/12-dog-years-in-human-years), [13](https://dogyears.info/13-dog-years-in-human-years), [14](https://dogyears.info/14-dog-years-in-human-years), [15](https://dogyears.info/15-dog-years-in-human-years) and [16](https://dogyears.info/16-dog-years-in-human-years).

[PDSA](https://www.pdsa.org.uk/what-we-do/blog/a-guide-to-senior-pet-food-and-feeding-your-ageing-pet) says the useful time to review the food is when the pet reaches the senior age range, and that a swap should be mixed in over 7 to 10 days. [The RSPCA](https://www.rspca.org.uk/adviceandwelfare/pets/dogs/health/seniordogs) says to ask your vet before you change an older dog's diet, and to change it gradually. [FEDIAF's Scientific Advisory Board](https://europeanpetfood.org/wp-content/uploads/2022/03/FEDIAF_SAB_Statement_Nutrition_of_Senior_Dogs_fin.pdf) says to split the daily ration into two or three meals at fixed times, and that fresh water should always be available. The RSPCA says the same about water.

FEDIAF uses a different cut-off in one energy table. [The 2025 nutritional guidelines](https://europeanpetfood.org/wp-content/uploads/2025/09/FEDIAF-Nutritional-Guidelines_2025.pdf), section 7.2.3.3 and Table VII-6, give dogs over 7 years a lower starting calorie allowance than dogs aged 3 to 7, and the text says dogs over seven may need 10 to 15 per cent less energy because activity often falls. The same chapter says that seven-year line should not be treated as a general rule, because the age when activity drops differs by breed and by dog, and that the table is only a starting point. A dog who is still running may need more than the table. Use the size table on this page for when we call a dog senior. Use body condition for how much to feed.

## What complete and complementary mean on a UK label

[UK Pet Food](https://www.ukpetfood.org/new-trade-zone/codes-of-practice/labelling.html) says a label has to state whether the product is complete or complementary, which species it is for, and how to feed it. The analytical constituents have to include the percentage of crude protein, crude oils and fats, crude fibre, crude ash, and moisture when moisture is over 14 per cent. [UK Pet Food's labelling fact sheet](https://www.ukpetfood.org/static/2d97c539-83d3-4e80-abb5eed0e5e9d588/UK-Pet-FoodFS39Pet-Food-Labelling.pdf) defines the two words. Complete means the food meets the dog's daily nutritional needs if you follow the feeding guidelines, with nothing else required. Complementary should be paired with other food. Mixers, treats and supplements are complementary. The fact sheet also says the label must name the animal and the life stage, and its example includes "senior".

The same split is in the [FEDIAF Nutritional Guidelines](https://europeanpetfood.org/wp-content/uploads/2025/09/FEDIAF-Nutritional-Guidelines_2025.pdf), which quote Regulation (EC) No 767/2009. A complete pet food is, by its composition, sufficient for a daily ration. A complementary pet food is sufficient for a daily ration only when it is used with other pet food. Those quoted definitions do not define "senior". If a complete food does not name a life stage, FEDIAF says it is assumed to be complete for all life stages and should meet the levels for early growth and reproduction. If it is for one life stage, the label has to say so.

If senior dog food is the only thing in the bowl, look for "complete" and a feeding amount. A pouch marked complementary is not a full diet on its own. The analytical constituents line tells you more than the word senior on the front of the bag.

## Wet or dry food for an older dog

Neither wet nor dry is automatically the healthier senior food. Both can be complete, and both can be complementary. [FEDIAF's advisory board](https://europeanpetfood.org/wp-content/uploads/2022/03/FEDIAF_SAB_Statement_Nutrition_of_Senior_Dogs_fin.pdf) says tooth loss and gum disease can get in the way of eating, that smell and taste can fade in very old dogs, and that texture, dry or wet, may matter for getting enough food in. Pouring warm water over dry food can help some dogs accept it.

[PDSA](https://www.pdsa.org.uk/what-we-do/blog/a-guide-to-senior-pet-food-and-feeding-your-ageing-pet) says that if the mouth is sore while you wait for dental treatment, or while it heals, a soft wet food is easier than kibble. That is a comfort measure. It is not a ranking of wet senior dog food. Bad breath, bleeding gums, dropping food, or refusing to chew are reasons to speak to a vet, not only to change the packet.

Wet food also comes up when the kidneys are the problem. [PDSA's page on chronic kidney disease](https://www.pdsa.org.uk/pet-help-and-advice/pet-health-hub/conditions/chronic-kidney-disease-in-dogs) says a special kidney diet is chosen with the vet, and that a wet kidney food is preferable because it adds water. A standard wet senior food from a shop is not that diet. If the dog will not eat the kidney food, PDSA says dry is better than no food, and to ask the vet rather than guess.

## What actually changes in a senior formula

FEDIAF's minimum tables for protein, fat, minerals and vitamins cover adult maintenance, early growth and reproduction, and late growth. They do not have a senior column. [The advisory board](https://europeanpetfood.org/wp-content/uploads/2022/03/FEDIAF_SAB_Statement_Nutrition_of_Senior_Dogs_fin.pdf) says there are still no experimental data for the energy or nutrient requirements of older dogs, so a senior food should at least meet the adult maintenance minimums, with the amount fed adjusted to body condition. A [2025 paper by German, Melgoza and Torres-Henderson](https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2025.1717409/full) in Frontiers in Veterinary Science looked at 61 adult and senior diets bought in two US shops and found the products labelled senior did not consistently differ from the adult ones. Fibre, fat and energy density varied widely. That study is not a UK shop survey, and it is not a list of brands to buy.

### Calories

The FEDIAF age chapter, linked above, says dogs over seven may need 10 to 15 per cent less energy than dogs aged three to seven, and that this is a starting point, not a rule for every dog. A very old dog who is eating poorly can need more energy, not less, to hold weight. [PDSA](https://www.pdsa.org.uk/what-we-do/blog/a-guide-to-senior-pet-food-and-feeding-your-ageing-pet) and [the RSPCA](https://www.rspca.org.uk/adviceandwelfare/pets/dogs/health/seniordogs) both say older dogs are often less active and so use fewer calories, and that you should watch the body, not only the packet. Weight gain and weight loss can each be a health problem.

### Protein

For a healthy older dog, FEDIAF's advisory board says protein should match the adult maintenance recommendation, and should be concentrated enough to limit loss of muscle if the dog eats less. The exception is disease, including advanced kidney disease, where the vet may change the amount or the type of protein. Do not pick a lower-protein bag on the assumption that every older dog needs less protein. PDSA describes the protein in senior food as there to help maintain muscle.

### Fibre

The advisory board says a diet for an older dog should contain enough crude fibre for normal gut movement. PDSA says senior foods often include more fibre. The German, Melgoza and Torres-Henderson paper found fibre was one of the nutrients that varied most between products. Read the crude fibre percentage on the label rather than assuming every senior bag is high in fibre.

### Joint support and other extras

PDSA says senior pet food often includes joint-support nutrients, antioxidants and fatty acids. FEDIAF does not set a required dose for a joint additive. Its advisory board says joint disease matters because a sore joint can reduce activity, and therefore the calories the dog needs, and that a specific disease needs veterinary advice and a diet outside a general senior guideline. On fats, the board says there is no separate senior recommendation beyond the adult minimums. It notes that docosahexaenoic acid (DHA), an omega-3 fat, was associated with better results on some cognitive tasks in one study of senior dogs, and that this is not a dose you can treat as a rule.

[UK Pet Food](https://www.ukpetfood.org/static/2d97c539-83d3-4e80-abb5eed0e5e9d588/UK-Pet-FoodFS39Pet-Food-Labelling.pdf) says it does not promote one complete food over another, because dogs and budgets differ. The practical check is the word complete, the analytical constituents, and whether weight and muscle stay steady. [Caring for an ageing dog](https://dogyears.info/caring-for-an-ageing-dog-uk-guide) covers weight, walks and the house around that. US owners comparing fresh food with kibble have a separate page, [fresh dog food vs kibble](https://dogyears.info/fresh-dog-food-vs-kibble-for-senior-dogs), which follows US sources rather than these UK labels.

## When to talk to a vet

Talk to a vet before you treat a shop senior food as the answer to a medical change. [When to take your senior dog to the vet](https://dogyears.info/when-to-take-senior-dog-to-vet) separates routine changes from the ones that should not wait.

- **Weight loss.** [PDSA](https://www.pdsa.org.uk/what-we-do/blog/a-guide-to-senior-pet-food-and-feeding-your-ageing-pet) says to contact a vet if an older pet loses weight quickly, or loses a lot of weight and looks underweight, without a change of diet. [The RSPCA](https://www.rspca.org.uk/adviceandwelfare/pets/dogs/health/seniordogs) says both weight loss and weight gain in an older dog can have a medical cause.
- **Kidney disease.** [PDSA](https://www.pdsa.org.uk/pet-help-and-advice/pet-health-hub/conditions/chronic-kidney-disease-in-dogs) describes chronic kidney disease as the kidneys slowly working less well. Signs can include drinking more, peeing more, a smaller appetite, weight loss, vomiting and low energy. Management includes a special kidney diet, with protein, sodium and phosphorus set for kidneys that are not working properly, ideally wet so the dog takes in more water. That is a veterinary diet. A senior bag from a shop is not a substitute, and any change of food should be gradual and agreed with the vet.
- **Dental problems.** PDSA lists bad breath, bleeding gums, dropping food and an unwillingness to chew as reasons to speak to a vet. Soft food can bridge the gap until the mouth is treated. It does not replace the treatment.

FEDIAF's advisory board makes the same split: its general senior statement does not cover dogs who already have a disease of old age. Those dogs need veterinary advice and a diet aimed at that disease.

## Common questions

### Is it worth buying senior dog food?

It can be, once the dog has reached the senior year for their size on the table above and the food is labelled complete. The definitions FEDIAF quotes from Regulation (EC) No 767/2009 cover complete and complementary food. They do not define senior, and the nutrient tables have no senior column. Feed to body condition. A shop senior food is not a treatment for unexplained weight loss, kidney disease or a sore mouth. Those need a vet.

### What is the best senior dog food in the UK?

There is no single best senior dog food in the UK, and this page does not rank brands or prices. UK Pet Food says it does not promote one complete food over another, because dogs and budgets differ. The healthiest dog food for a senior dog is the complete food that keeps that dog's appetite, stools, energy and body condition steady. Read the feeding guide and the analytical constituents, then judge the dog.

### What is the best senior wet dog food in the UK?

There is no single best wet senior dog food in the UK either. Wet food helps when teeth or gums make kibble hard to eat, and a vet may choose a wet kidney diet so the dog takes in more water. A wet food is a full diet only if the label says complete. A complementary pouch, mixer or treat is not.

### Check the senior year for your dog

The calculator uses the same Royal Kennel Club size bands as the table above, including a named breed.

[Go to the calculator](https://dogyears.info/)

Related reading: [Signs your dog is a senior](https://dogyears.info/signs-your-dog-is-a-senior) · [Dog life stages](https://dogyears.info/dog-life-stages-explained) · [Small vs large breed ageing](https://dogyears.info/small-vs-large-breed-ageing) · [When to take your senior dog to the vet](https://dogyears.info/when-to-take-senior-dog-to-vet) · [Caring for an ageing dog](https://dogyears.info/caring-for-an-ageing-dog-uk-guide) · [10 in dog years](https://dogyears.info/10-dog-years-in-human-years) · [16 in dog years](https://dogyears.info/16-dog-years-in-human-years) · [Fresh dog food vs kibble (US)](https://dogyears.info/fresh-dog-food-vs-kibble-for-senior-dogs) · [All guides](https://dogyears.info/guides)

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