Your Dog's Nutritional Needs: A Complete Guide

Feeding your dog goes far beyond filling the bowl: their energy needs are worked out using specific formulas such as MER (kcal/day) = 110 × body weight (kg)^0.75. This article breaks down the six essential nutrients and how to adjust calories to their lifestyle, drawing on industry reference standards.

How to Calculate the Calories Your Dog Needs Each Day

Six pillars support any dog's diet: protein, fat, carbohydrate, vitamins, minerals and water. Protein does the most work — it repairs tissue, supports the immune system and takes part in synthesising enzymes and hormones — and has to come from quality animal sources: chicken, lamb, fish. For adult dry kibble, the minimums AAFCO requires are 18% protein and 5.5% fat, as set out in "Nutrient Requirements of Dogs" (1963).

The starting point for working out a dog's daily calories is MER, the maintenance energy requirement. The formula involves multiplying 110 by their weight in kilograms raised to the power of 0.75. That exponent changes everything. Energy demand grows allometrically, and a dog weighing twice as much does not eat twice the calories, not by a long way. This is confirmed by the analysis in "Energy requirements of adult dogs: a meta-analysis" (2014).

A 15 kg dog serves as a concrete example. The calculation gives 110 × (15^0.75) = 110 × 7.62 ≈ 838 kcal a day. That figure applies to a neutered adult with moderate activity; from there, it all depends on the individual. A working or highly active dog can multiply that value by 1.6 or even 2. A neutered senior living a quiet life may need to drop to a factor of 0.8 so their weight does not creep up.

These calculations give guidance, not certainty. What confirms whether the ration is right is the dog themselves, or more precisely, their body condition. If the ribs are hard to feel under the coat, intake is excessive. If they are visible to the eye, on the other hand, it shows the animal is eating below what they need and calories should be raised gradually. MER gives the map; the dog is the territory.

AAFCO and FEDIAF Nutrient Profiles: What It Means for a Kibble to Be "Complete"

AAFCO (the Association of American Feed Control Officials) and FEDIAF (the European Pet Food Industry Federation) set the minimums and maximums any commercial food has to reach to be declared "complete and balanced" for a given life stage.

The key is on the packaging itself. When a kibble is advertised as "complete for adult dogs", that means its formulation meets the nutrient levels of the AAFCO or FEDIAF profiles for adult maintenance. There are two ways to verify this. The first is analysing the product's final composition; the second, considerably more robust, is passing an actual feeding trial, in which the food has to keep the animals in good condition over an extended period.

We are talking about standards covering everything from protein to selenium or vitamin K, covering absolutely everything a dog needs. A food meeting these profiles minimises the risk of shortfalls and excesses. And watch out: if the packaging carries no explicit statement of completeness, that product should be treated as a complement or for occasional use, never as the backbone of the animal's daily diet.

Nutrition by Life Stage: Puppy, Adult, Senior and Pregnant

A puppy growing at full speed has very little in common, nutritionally speaking, with an eight-year-old Labrador who no longer goes out running. The life stage changes everything: the energy the animal needs, the protein, the minerals, the way their body makes use of what they eat. And giving everyone the same kibble because "it's a good brand" is one of the most common mistakes.

During growth, energy and protein demands are very high. But more is not always better. Excess calcium can cause damage just as serious as a shortfall, which matters especially in large and giant breeds, where growing too fast overloads the joints before the skeleton is ready. Kibbles designed for these dogs limit fat and keep calcium below 1.8% on a dry-matter basis to slow that growth rate and protect the locomotor system, according to "Feeding large-breed puppies" (2010).

The adult dog, with their skeleton already formed and their metabolism stable, basically needs to maintain what they have. Muscle mass, the right weight, organs working well. A maintenance diet aims for that balance without overdoing energy, which in a dog with moderate activity translates directly into extra kilos.

The senior stage brings a different picture. Metabolism slows, the dog moves less, and if they keep eating what they did at three years old, they put on weight. Cutting calories does not mean impoverishing the diet, though. Many senior foods include glucosamine, chondroitin or antioxidants that help manage joint wear and cellular ageing. Watch out here, because an active older dog does not need the same as a sedentary one.

Pregnant or nursing bitches are another chapter entirely. Their needs almost double in energy, with a considerable increase in protein and calcium to cover the pups' development during pregnancy and support milk production afterwards. Underfeeding a bitch during this period has direct consequences for the litter.

Switching between stages should not be done abruptly. Moving from a growth kibble to an adult one is recommended once the dog reaches skeletal maturity, which in small breeds arrives around 10-12 months and in giant breeds can be delayed until 18-24 months. Ignoring these timings has consequences: obesity in overfed adults, bone deformities in puppies who grew too fast, malnutrition in nursing bitches. Specific problems, with long-term consequences.

How to Choose the Kibble That Genuinely Suits Your Dog

The ideal kibble does not exist in the abstract. It depends on your dog, their life stage, their size, how much they move and whether they have any health problem. The first thing to check on the packaging is that it carries the phrase "complete and balanced for", a certification set by bodies such as AAFCO or FEDIAF. From there, it is time to read the ingredient list and the analytical composition, where the percentages of crude protein and crude fat will tell you far more than the sack's design or its price.

If the dog has diagnosed allergies or intolerances, novel-protein or hydrolysed formulas are the way to go. For one prone to weight gain, a light kibble with lower energy density and good fibre content helps keep them satisfied without going over on calories. Breeds with high physical activity, such as the Spanish Water Dog, need a greater supply of quality fat to keep up the pace. And on price, watch out: a cheap kibble that does not cover their real needs is never the most economical option, and a premium one well matched to your dog pays off more than it seems, according to "Comparison of Key Nutrient Content of Commercial Puppy Foods with Canine…" (2023).

When you make the switch, do not do it all at once. The sensible approach is 7-10 days mixing the new kibble with the old one in increasing proportions, giving the gut microbiota time to adapt and thereby avoiding diarrhoea or the dog rejecting the food outright. Their coat, body condition and stools are, from there, the most reliable indicators of whether the choice was the right one.

Signs That Point to Nutritional Deficiencies in Your Dog

The gums are one of the easiest checks, and one of the most overlooked. A rich pink colour is normal; when they look pale, something is off — sometimes it is anaemia, other times an iron shortfall. The coat speaks too. If it is dull and lifeless, with constant flaking, it almost always points to a diet low in essential fatty acids or zinc. And if on top of that there is compulsive licking of the paws or small wounds that take weeks to heal, the B vitamins or the quality of the protein deserve a review.

A dog gaining or losing weight without you having changed their rations deserves attention. Their diet could be failing even if the amounts seem right. Frequent wind, pasty stools or diarrhoea that comes and goes almost always point to intolerances or a poorly balanced fibre level. Watch too for a dog who repeatedly drags themselves along the floor — it can be an anal gland problem, and that problem often improves noticeably when fibre in the diet is increased.

Some dogs eat earth, stones or their own faeces. They do it to make up for something they are lacking, usually minerals. Apathy can also hide a deficiency. If a dog who used to pull on the lead now cannot be bothered with a walk, their diet may not be giving them the energy they need. These changes tend to creep in slowly, settling in bit by bit, and when they are spotted before becoming chronic, gradual adjustments to feeding are usually enough to turn them around.

The Importance of Water in Canine Nutrition: How Much Should Your Dog Drink?

Water is the most critical nutrient; a dog can lose almost all their fat and half their body protein and survive, but a 10% loss of body water is fatal. It is involved in practically every physiological process: thermoregulation through panting, digestion, transporting nutrients, eliminating waste through urine, and lubricating joints.

This amount includes not only the water they drink directly, but also the moisture present in their food. A dog fed a wet or natural diet will take in a significant amount of water with their food, while one who only eats dry kibble will need to drink far more to make up for it.

Having fresh, clean water freely available at all times is non-negotiable. It should be topped up at least once a day and the bowls washed regularly to prevent bacteria building up. A noticeable drop in water intake, or conversely an excessive, sudden increase (polydipsia), are warning signs that call for prompt veterinary assessment to rule out underlying problems such as diabetes, kidney disease or infections.

Guaranteeing proper hydration with fresh, clean water is fundamental to their health, alongside complete nutrition meeting the AAFCO/FEDIAF profiles.

Matching their food to each dog's specific needs — taking into account their age, activity level and health — is the basis of proper nutrition; which is why the sensible approach is to review their diet periodically with a vet, adapting it to the changes they go through over their life.