Adapting the food to the dog’s physiological condition


The term physiological condition (or state) refers to the dog’s natural life stages. This includes its age, which has already been discussed, as well as sexual status. For instance, gestating and lactating females have very high, very specific nutritional requirements. Although artificial in origin, neutering (the removal of the testicles or the ovaries and uterus) is also a physiological condition. In this case, the dog’s metabolism will be modified for the greater part of its life. As a result, it will have specific nutritional requirements.

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Stud dogs require high-quality food


Stud dogs do not have any particular specific nutritional requirements, although, even more than a dog in the maintenance phase, they will require a high-quality balanced food to ensure they are in perfect shape. Stud dogs must be in optimal physical condition – neither too skinny nor too fat – as this will have an adverse effect on semen quality, with a healthy skin, (no scabs or dandruff) and a glossy coat. As explained above, the dog’s oral hygiene needs to be impeccable, bearing in mind that the bacteria that cause periodontal disease can spread to other parts of the body. This can affect the prostate, which plays a major role in reproduction.

A high-quality highly digestible balanced food is essential, as even when there are no clinical signs, any imperfections will have an inevitable impact on semen quality and therefore fertility.

Preparing the bitch for mating

Bitches, preferably young adults, must always be in optimal physical condition when they are mated. They should not suffer from a chronic disease or any other problem that could have an adverse impact on gestation or lactation and even put their life at risk. Unfortunately, some owners are less scrupulous than others. Body condition is a fundamental criterion, both in terms of fertility (the capacity for reproduction) and prolificacy (the capacity for producing larger litters). The reproduction parameters will be below average if the bitch is overweight or underweight. Show females are often felt to look more pleasing if they are a little overweight – in itself contentious – so it is advisable for them to slim down a little before being mated. If weight adjustment is necessary, the diet should be adapted during anoestrus, which will give bitches plenty of time to reach their optimal weight. In practice, energy (calorie) intake should be increased (where a bitch is too thin) or decreased (where a bitch is too heavy) by approximately 10% in the months prior to oestrus.

In a technique known as flushing, the bitch’s energy intake is increased during the pre-ovulation phase to stimulate oocyte maturation and release. Flushing is of little or no benefit to bitches with optimal body condition or those who are already overweight. Energy intake may be increased by 5-10% during pro-oestrus to optimise fertility and litter size if the bitch is underweight. While this is common practice with livestock (sheep and cows), its effectiveness is yet to be proven in dogs. Again, the best approach is to ensure that females are in perfect physical condition.

As with stud dogs, bitches used in reproduction must always be given high-quality, highly digestible food to ensure that their requirements – comprising over fifty nutrients - are met in full. The most important thing here is that intake is tailored to the size of the bitch, regardless of physiological state.

Gestation: the need to adapt the food gradually

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The quality and quantity of food given to gestating bitches needs to be adapted to the physiological requirements of gestation, which differ depending on the expected number of puppies in the litter. Clearly, a bitch pregnant with nine puppies will have different requirements from one carrying just three. The size of the dog is also important, of course. If the litter size is the same, the demands will be greater on a small-breed female than on a large-breed female. This becomes clear when we compare the birth weight of the puppy with the weight of its mother, a ratio that is four times higher in Yorkshire Terriers than it is in Saint Bernards. In small breeds, the puppies are more mature at birth.


The quality and quantity of food given to gestating bitches need to be adapted to the physiological requirements of gestation.


Nutritional requirements remain unchanged until week five of gestation. This is the period of organogenesis, when the foetuses’ internal organs develop. A high-quality maintenance food adapted to the bitch’s size will usually be sufficient during this phase. Foetal growth speeds up in week six, growing exponentially. A foetus will put on 80% of its birth weight in the final three weeks of gestation. The quality and quantity of the mother’s intake needs to be increased to cope with this intense growth. Her uterus will also have to expand, leaving less room for the stomach and the gut. As a result, nutritional requirements increase just as the “processing space” decreases. This challenge is solved by feeding bitches a food with a higher energy and nutrient concentration around the end of gestation. Increasing fat content is a common way of concentrating intake. This also improves the food’s palatability, which can at least partially offset the lack of appetite observed in mothers towards the end of gestation.

Energy intake

The energy content of a food must take due account of the reduced stomach capacity of bitches at the end of gestation and enable the storing of glycogen reserves (glucose storage) in the liver of the foetuses. Without these reserves, newborns will be at risk of potentially lethal hypoglycaemia.

Indeed, more than 50% of foetal development is fuelled by glucose. So while it is theoretically possible to feed dogs a glucose-free diet (bearing in mind that as carnivores they are able to make glucose from protein and fat), this practice is highly inadvisable in females at the end of gestation, due to the serious risks to them and their puppies.

The total energy requirements of gestating females are made up of their own maintenance requirements, the growth and maintenance requirements of their foetuses and the requirements of the placenta and the distended uterus. These total requirements will gradually increase from week six of gestation. By the end of gestation they will have increased by 30-50%, depending on the size of the litter. For example, the energy requirements of a 12kg Cocker Spaniel carrying six foetuses will increase by 40% by the end of gestation.

Just before labour, bitches often lose their appetite, due to tiredness or discomfort, so they should be given a highly digestible, palatable food with a high energy content. The daily amount should preferably be spread over several servings over the course of the day. Those with a finicky appetite may be given free access to their bowl, although the daily ration must, of course, never be exceeded. Excessive fat build-up in the birth canal will hamper birth, possibly leading to unwanted complications. The size of the litter and the size of the bitch need to be taken into account, but, on average, her weight will increase by 25% during the gestation phase. About half of this weight will be lost during whelping (puppies, liquids and umbilical sacs). Females only recover their optimal weight at the end of lactation. During at least the first six weeks of gestation, ad libitum feeding should not be practised.

© Diffomédia/Royal Canin

Protein intake

Newborn puppies are about 80% water, 15% protein (around 75% protein by dry weight), 1.5% fat and around 2% minerals. The intake and deposition of protein is an essential part of gestation. The body does not build up protein reserves, as it does carbohydrate reserves (in the liver and muscles as glycogen) and fat reserves (in fat tissue). All protein is put to immediate use. The synthesis of protein requires an intake of energy and protein in the diet. The foetuses will continue to grow in gestating bitches that do not take in sufficient protein, because it will be taken from the mother’s muscle mass. This muscle wastage will be easy to see on the lower back. If the vertebrae are visible the dog is suffering from energy and or protein deficiency. While this is not life-threatening for the mother, it does put the puppies at mortal risk and it will compromise the mother’s capacity for lactation when the time comes. It is therefore essential to increase the bitch’s protein intake at the end of gestation.

Mineral and vitamin intake

© Diffomédia/Royal Canin

First and foremost, it is important to realise that all nutrients have the ability to be potentially harmful, depending on the intake quantity (immediate toxicity) and the intake term (accumulative or chronic toxicity).

Gestating females need to take in more calcium (around 60% by the end of gestation) so that the bones of their foetuses are able to calcify. On the other hand, excessive intake of calcium is extremely harmful. Various hormones rigorously regulate the blood calcium level, including parathormone to increase it and calcitonin to reduce it. An excessive intake will increase blood calcium for a limited time, triggering a counter-regulation mechanism to repress parathormone. If this occurs, when calcium is required, due to labour or lactation, the bitch will be at risk of hypocalcaemia (eclampsia), a condition that threatens both mother and puppies.

Particular attention to the food’s vitamin A content is important, as this vitamin passes through the placental barrier, providing protection to the epithelium of newborns. At the end of gestation, the vitamin A content can be twice the recommended content in a maintenance food. Again, however, an excessive vitamin A intake can have toxic effects. At 40,000 IU/kg and above, it can lead to foetal deformity and death. Sensitivity to vitamin A is greater at the start of organogenesis, between days 17 and 22 of gestation.

To summarise, the following points should be remembered when feeding a gestating bitch:

– Her energy requirements will increase by around 10% per week from week six of gestation. Kibbles are strongly recommended, as wet food contains 80% water (compared with 10% water in kibbles), which requires a much higher volume of food.

Although home-prepared food is an option, it needs to be formulated or checked by a veterinarian, and it also entails a very high volume intake.

– The energy concentration of this food must be high (metabolisable energy between 3,800 and 4,300 kcal/kg of food, based on weight, activity and temperament) and its digestibility should be easy to evaluate based on the volume and consistency of the faeces.

– The protein content must be increased (to between 25% and 36% depending on the expected litter size).

– The calcification of the foetal skeleton at the end of gestation demands increased intake of the minerals that make up bone (mainly calcium and phosphorus). The calcium content must be based on the energy concentration of the food, which determines the volume ingested by the female. It must never be more than 4 g per 1000 kilocalories ingested, so as to limit the risks of the parathyroid glands failing to respond adequately, which may lead to eclampsia. The phosphorus content is generally adjusted to maintain the phosphorus to calcium ratio between 1.2 and 1.4 (physiological proportion for bone constituents).

– The mother’s weight at the end of gestation must not exceed 25% of her maintenance weight to reduce the risk of difficulties during birth due to excessive fat deposits in the birth canal.

A high-quality complete dry food specially formulated for puppies – with a high-energy concentration and increased calcium and protein content – is generally appropriate from week five onwards, bearing in mind that puppies have similar requirements to gestating females. It should never be supplemented. Food adapted to the size or breed of the bitch is also worth considering, because small breeds do not have the same requirements as large breeds.

Learn more

Good appetite and a rapid growth were highly appreciated in nutritional studies in the past. Is it time to revise that in the light of what we know today?

Although appetite and growth still are to be considered indicators of health and nutritional balance, we have learned to know that maximal growth is not compatible with optimal skeletal characteristics in large sized dog breeds and other mammals (like poultry, fowls and swine) selected for growth performance.

Maximal growth is achieved by nutritional composition and amount fed. Unfortunately also a balanced diet can be overfed and result in skeletal disturbances despite an optimal composition. Young rapidly growing individuals therefore should be fed a balanced diet but in amounts restricted to allow proper skeletal development.

In large sized dog breeds meant to live a long and healthy life that is even more important as the nutrition during growth also prepares for sustainability later in life.


Professor Ake Hedhammar,
Veterinary doctor,
University of Veterinary Medicine Upsalla, (Sweden)

Lactation is the most demanding life stage


Unlike gestation, lactation involves a considerable increase in the nutritional needs of the bitch, given the exceptional richness, in terms of calcium, energy and protein, of the milk she produces for her litter (1,200-1,500 kcal per kg depending on the breed and the day of lactation, compared with just 750 kcal per kg in cow’s milk). The quantity produced will depend on the number of puppies feeding. The moment of peak milk production comes during week four of lactation. Throughout the period of lactation, the goal will be to limit the mother’s weight loss, which is inevitable when the litter is large.

Lactating females often continue to eat the same food they consumed at the end of gestation, with the following characteristics:


Lactation involves a considerable increase in the nutritional needs of the bitch, given the exceptional richness of the milk she produces.


- High palatability to stimulate her appetite, which is often lost at the start of lactation. The fat and protein content contributes to this.

- Kibble shape, size and hardness tailored to the dog’s size to ensure she has no problems eating.

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Calculating the quantity of milk the bitch will produce

© Diffomédia/Royal Canin

TP = (W x c) + 0.1 x W x (N – 4)
TP: total milk production in kg
W: maintenance weight of the female in kg
c: coefficient of the female’s size
N: number of puppies feeding


For example, a Golden Retriever with a maintenance weight of 27kg has a litter of 9 puppies and has a total milk production of around 67kg (where W = 27kg; c = 2 and N = 9) over a period of two months, corresponding to energy expenditure of almost 9110 kcal (1350 kcal/kg of milk). If this energy expenditure is spread over the two months of lactation, the female needs to take in an average of 1500 kcal per day to produce that milk...and her maintenance energy requirement is around 1500 kcal. The female’s milk production can be calculated for the first four weeks of lactation as follows.

Water intake should not be forgotten. Maternal milk contains almost 80% water, so 67kg of milk corresponds to more than 50 litres of water or just less than 1 litre per day on average for this Golden Retriever, just to meet milk production needs. The ambient temperature also needs to be taken into consideration, as it is higher for the benefit of the puppies, so the female must have permanent access to plenty of clean water.

© Diffomédia/Royal Canin

- Very high energy concentration (more than 4000 kcal/kg) to ensure she can take in large quantities of energy and nutrients in small volumes. Although home prepared food is possible, a massive increase in the fat content would be needed to increase the energy concentration sufficiently to keep the feeding volume down to a reasonable level and some bitches may not be able to tolerate this. There is also a health risk, associated with the difficulty of conserving these preparations at ambient temperature.

- Higher protein, fat, mineral and vitamin contents, depending on the size of the dog.

- High-quality ingredients to ensure optimal digestibility (smaller, well-formed faeces, no bloat or flatulence).

Clean water should always be accessible in large quantities and replenished several times a day. Remember that milk is almost 80% water.

Females with large litters must also have unlimited access to food, so that they can eat when they want. This should be placed close by (the bitch will not leave her puppies during the first few days) and off the ground (at head height, for example). For hygiene reasons, the bowl should be emptied, cleaned and replenished at least twice a day, even if not all the kibbles have been eaten. Having more than one bowl is undoubtedly the most practical solution.

The puppies may begin to consume the bitch’s lactation food after three to four weeks, initiating the weaning period. A bowl should always be placed at head height for the exclusive use of the mother, so that her intake can be monitored; this is important as weaning begins at the time of peak lactation.

A starter food is a better solution at this point, as it covers the suckling mother’s requirements while also enabling the puppies to wean independently.

The harmonious growth of the litter – i.e. lively but satiated puppies – is naturally an indirect source of information on the quality of lactation and thus the mother’s health. Breed-specific prepared foods are available that are specially formulated for females in this life stage, ensuring that their nutritional requirements are fully met. Mothers of large litters will inevitably lose weight; the main thing is to ensure that they begin to recover their optimal weight when their puppies are weaning. If they do not, their diet will have to be reviewed. A bitch should not be mated again until she has returned to her optimal weight.

Neutering changes the nutritional needs of both males and females


Neutering is a form of surgical contraception that can be carried out on either sex. Castration specifically refers to the removal of the male testicles.

Studies show that the reduction of sexual hormones (testosterone in males, oestrogen and progesterone in females) following neutering will lead to a lowering of the maintenance energy requirement by 20-30%. At the same time, appetite will most often increase, which is why weight gain is often seen after neutering.


This is not always the case, however, and should not be viewed as inevitable. Weight gain can be avoided in recently neutered dogs of either sex if a few precautions are taken.

The animal should be weighed every fifteen days during the first three months after surgery, then every month for the next three months. Any weight gain after six months of normal weight is not related to neutering. It is important to keep a record of these measurements, preferably in the form of a graph, which is an easy way of visualising the situation. It is just as easy to monitor body condition: simply place a hand flat on each side of the animal’s thorax, behind the elbows, and move them towards the back without applying pressure (the skin will move at the same time). If the ribs are clearly discernable without applying pressure everything is as it should be and the animal will be at its optimal weight. If pressure has to be applied to count the ribs the animal is overweight, and if they cannot be counted when pressure is applied the dog is obese. This simple examination enables action to be taken quickly if the dog is putting on weight.

Weight gain in excess of 5% in one month (i.e. 500 grams in a 10kg dog) is a reason to visit a veterinarian, who will fine-tune or even radically change the dog’s food. Reducing daily intake by 10% is a possible first step if the animal has put on just a little weight. The problem is that the dog’s appetite actually increases after neutering, so neither dog nor owner are likely to be happy with this. Reducing the maintenance intake by more than 10% may result in deficiencies, since nutrient intakes are reduced across the board. The best solution is to discuss the situation with a veterinarian, because there are prepared foods available specially formulated for neutered or sedentary animals. These foods have a low energy concentration compared with maintenance foods, which ensures that the volume of meals remains reasonable. This reduction in the energy concentration must not lead to a reduction in nutrient intake (protein, minerals, vitamins), which is why these foods have a higher nutrient concentration. Lastly, studies into satiation (the feeling of fullness) have led to the formulation of foods that seem to satisfy the dog’s hunger more quickly and cause it to consume smaller quantities. These are all important factors in this field.


Neutered dogs certainly need plenty of exercise. It is a good idea to increase the activity level, as physical exercise leads to more energy being expended, countering the effects of neutering.


Neutered dogs certainly need plenty of exercise. It is a good idea to increase the activity level, as physical exercise leads to more energy being expended, countering the effects of neutering.

It is worth reiterating that dogs should not be fed leftovers and that any treats should be specially made for dogs and should not represent more than 10% of their daily energy intake. Fruit, such as apples, makes a good treat used in moderation, and many dogs like it. Given in a reasonable quantity (for example, half an apple a day for a Labrador), fruit can be used as a reward, without running the risk of weight gain.

Grapes and raisins are toxic to dogs.

© Diffomédia/Royal Canin
Learn more

How can you tell whether your dog is allergic to certain foods?

A food allergy in dogs is expressed by itching in the feet, ears, face, abdomen and anus. Secondary infections caused by yeast or bacteria are common. Here the itching is persistent or becomes more intense. In some cases, as well as skin problems, there are gastrointestinal problems, which may be indicated by watery faeces, chronic diarrhoea, gut noises and vomiting.

Diagnosis is by elimination. Blood tests are not diagnostic. Based on the dog’s precise dietary history, a single source of protein and of carbohydrate is chosen that the patient has never eaten before. If the symptoms clear up after 8 to 12 days of this strict diet, the dog should be fed the original food in a provocation test. If the red blotches and itching come back within 14 days, the diagnosis is confirmed.


Claudia Nett,
Doctor of Veterinary Medicine,

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