Feeding a Dog by Life Stage: Puppy, Adult and Senior

A dog’s nutritional requirements are not constant. They change substantially through growth, again at maturity, and again with age — and one of those transitions, in large-breed puppies, has consequences that cannot be undone.

The label claim that matters

Every complete food carries a life stage statement based on AAFCO or FEDIAF nutrient profiles:

• Growth and reproduction — puppies and pregnant or nursing bitches
• Adult maintenance
• All life stages — meets the growth profile, so it is nutrient-dense enough for a puppy and usually too rich for a sedentary adult

There is no official “senior” profile in either system. Senior foods are formulated to adult maintenance standards, with adjustments the manufacturer judges appropriate. That is not a criticism — many are sensibly formulated — but it means “senior” is a marketing category, not a regulatory one, and quality varies more than in other categories.

Puppies

Puppies need more of almost everything per kilogram of body weight: more calories, more protein, more calcium and phosphorus, and DHA for brain and retinal development.

Feeding frequency:

• 8 to 12 weeks: four meals a day
• 3 to 6 months: three meals a day
• 6 months onwards: two meals a day

Small and toy breeds need the higher frequency for longer, because they are prone to low blood sugar when very young.

How much: start with the manufacturer’s guide for expected adult weight, then adjust by body condition every fortnight. You should be able to feel ribs easily under a thin covering. A puppy with a visible waist from above and a slight tuck from the side is right.

The large-breed puppy question

This is the most important nutritional decision most owners will ever make, and it is easy to get wrong.

Puppies expected to mature over about 25kg must be fed a large-breed puppy formula or an all-life-stages food with a controlled calcium content.

The reason: unlike adult dogs, puppies cannot fully regulate how much calcium they absorb from the gut. Excess calcium during rapid growth is directly linked to developmental orthopaedic disease — hip and elbow dysplasia, osteochondrosis, and a set of skeletal abnormalities that cause lifelong pain.

Three specific rules:

1. Use a food formulated for large-breed growth, with calcium controlled to roughly 1.0 to 1.8 percent on a dry matter basis
2. Never add a calcium supplement to a complete puppy food. This is the most common way owners cause the problem they are trying to prevent
3. Keep growth steady rather than maximal. Growing a large-breed puppy as fast as possible is precisely what you do not want

When to switch to adult food

• Small breeds (under 10kg): 9 to 12 months
• Medium breeds: 12 months
• Large breeds (25 to 45kg): 15 to 18 months
• Giant breeds: 18 to 24 months

Neutering matters too. Metabolic rate drops noticeably after neutering, and a common mistake is keeping portions identical. If your dog is neutered, expect to reduce food by roughly ten to twenty percent and monitor body condition closely over the following months.

Switch over five to seven days: 25 percent new food, then 50, then 75, then 100.

Adult dogs

The goal here is boring and difficult: hold a lean body condition for a decade.

• Feed to body condition, not to the bag. The guidelines are averages and individual requirements vary by up to 30 percent
• Weigh the food. Cups are wildly inaccurate
• Count treats within the daily total, keeping them under ten percent
• Reassess after any change in activity, after neutering, and every autumn when walks get shorter

Working, sporting and highly active dogs need more calories and often more fat. Most pet dogs need considerably less than the bag suggests.

Senior dogs

Dogs are generally considered senior at around seven, earlier for giant breeds and later for small ones. What changes:

Calories. Most seniors need fewer, because activity declines. But a substantial minority — particularly thin older dogs — need more, because absorption becomes less efficient. Both directions exist and body condition tells you which dog you have.

Protein. The old advice to restrict protein in healthy older dogs has been abandoned. Ageing dogs lose muscle mass, and adequate high-quality protein helps preserve it. Protein restriction is appropriate for diagnosed kidney disease, on veterinary advice, not as a precaution.

Joint support. Many senior diets include omega-3s and joint supplements.

Texture and palatability. Sense of smell declines, dental disease is common, and a food that is easier to eat matters. Warming food or adding water increases aroma considerably.

Water. Older dogs are more prone to dehydration and to kidney problems. Wet food helps.

Food storage matters more than people think

Fats oxidise. An open bag of kibble left in a warm kitchen loses palatability and some nutritional value within weeks, and rancid fat causes digestive upset.

Keep food somewhere cool and dark, use it within about six weeks of opening, and never top up old food with new in the same container.