From maturity to old age


The dog will eventually pass the halfway point in its life. Externally, this life stage is generally no different to early adulthood. However cell modifications take place that, while invisible to the naked eye, pave the way for more conspicuous changes later. The ageing process is a slow, gradual one.

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Before old age: maturity


Medical and nutritional measures should be put in place as quickly as possible for dogs suffering from a chronic disease, such as arthritis or heart failure, to help slow down its development. The dog’s weight should be monitored closely so that any change upwards or downwards can be quickly detected and the diet adapted to its breed, age and size. The dog’s teeth demand the same special monitoring now as they do throughout life.


Ageing is a natural, gradual biological process that reduces the body’s ability to maintain its physiological balance and increases its susceptibility to disease. It is responsible for changes to cells, organs and metabolism in dogs that are increasingly being identified and described. As sad and inevitable as it is, there are ways to slow down the process or at least avoid speeding it up. The main thing is to prevent disease where possible, identify it at the earliest opportunity if it does strike and treat it vigorously to preserve the dog’s health as long as possible. Preventative medicine is the favoured approach here, too.

When is a dog considered old?

Age is a number not a condition. Maturity and old age are arbitrary concepts defined on the basis of life expectancy. A dog is regarded as mature when it reaches the midway point in its expected lifespan and it is old when it has three quarters of its expected lifespan behind it. Of course, dogs of different sizes do not age in the same way or at the same rate. Small breeds have a longer life expectancy than large breeds, so a small dog will age slowly. Conversely, large dogs take longer to grow to adulthood and age faster. That clearly means that they do not have the same needs.

© Diffomédia/Royal Canin

Consequences of ageing for the body

Ageing is not a disease, it is a natural process that affects the entire body. No organ or system is spared. That said, individual susceptibility or the predisposition of an organ will contribute to the development of a disease. The main thing is to understand the ageing mechanism to slow down its effects.

Ageing has a number of effects on the body of a dog:

• Fat deposits increase. Dogs tend to put on weight as they grow older. The animal builds up its fat deposits at the expense of muscle mass. When a lot of muscle mass is lost, the animal’s mobility will be affected, leading it to expend less energy. As a result, the dog puts on more weight, loses more muscle mass, and so on. This makes it vital to monitor the animal’s body condition so that it is prevented from putting on weight and losing muscle mass. It is also essential to treat any pain the dog may have that might prevent it from exercising.

• The accumulation of fat is accompanied by dehydration. A newborn puppy is 85% water, while an ageing dog is just 60% water. This loss of water plays a role in the ageing process.

The digestive functions deteriorate:

•The teeth are a common source of problems in ageing dogs. Build up of plaque causes gum inflammation and infections (periodontal disease), which can lead to the teeth falling out. The animal will find eating more difficult because chewing is painful. As well as the unpleasant bad breath this produces, the proliferation of bacteria that spread in the body can cause damage to other organs. The immune system is permanently working overtime, which puts a great strain on the body, making it more susceptible to infection. Dental hygiene is essential throughout the dog’s life, but especially so in ageing dogs. Instigating dental hygiene in the puppy is a preventive measure that will help to preserve the quality and health of its teeth for the whole of its life. Diet has an important role to play here. The formulation and even the physical characteristics of kibbles – size, shape, hardness – can help to slow down the build up of dental plaque.

© Diffomédia/Royal Canin

• Digestive transit (the progression of food from the stomach to the anus) slows down in older dogs, linked to reduced muscle tone in the intestine and a drop in digestive secretions. This exposes the dog to constipation often followed by diarrhoea. These problems can be controlled by means of an adapted diet (fibre content).

• Just like the rest of the body, the intestine starts to work less efficiently. Its digestive performance is reduced a little, it absorbs nutrients in lower quantities and it takes more time to adapt to a change of diet. A high-quality, easily digestible food minimises these effects.

Other bodily functions gradually lose their ability to adapt:

• Due to the reduction in immune protection, ageing dogs are more susceptible to infection.

• The kidneys, liver and heart gradually become less efficient, which can sometimes result in organ failure. The organs and the body as a whole can be given extra support by adapting the diet, thus slowing down the degeneration process and improving quality of life.

• Slow decalcification occurs, weakening the skeleton.

• Metabolism constantly produces toxins throughout the dog’s life. Some of these cause the destruction of cell membranes in a process known as oxidative stress. The body has a number of mechanisms to repair this, but these are less effective in ageing dogs. This means that these animals are more open to attack. Again, however, there are ways to limit this stress, especially through dietary measures.

• Tumours, some but not all of them cancerous, start to develop.

• The hair loses its colour and the skin becomes less supple and more fragile.

The senses and behaviour are modified:

• Impaired sight, sometimes even blindness, is common.

• Smell may be impaired, possibly causing a loss of appetite.

It is important to keep making sure the dog remains active even as it (and perhaps its owner) grows older. An animal that moves around less, is less attentive or too quiet should be examined by a veterinarian. It is essential that the inevitable effects of ageing are not confused with a disability due to organ impairment.

Arthritis can have a severe impact on the dog’s quality of life:

A dog with arthritis may not show obvious signs of discomfort, but it will be less inclined to go for a long walk or play. Arthritis involves dull, piercing pain, which must be relieved. Again, it is important to differentiate between the effects of a specific disease and the expected effects of ageing.

© Diffomédia/Royal Canin

Any dietary errors during the final part of life, indeed at any time, can speed up the ageing process in dogs and so the following rules need to be followed:


• Obesity needs to be prevented. The daily feeding amount can be reduced by 10% in response to the dog’s reduced physical activity. If that proves inadequate, the best option is to consult a veterinarian about the choice of an appropriate food to reduce energy intake but ensure the dog is not exposed to the risk of nutrient deficiencies.

• The protein content in the diet needs to be at least 25% to ensure an optimal balance and enable the dog to fight stress and maintain its immune system. In dogs with kidney or liver disease, the veterinarian will prescribe a specific lower protein diet. It is important to remember that restricting protein intake will not prevent kidney failure and may even reduce the animal’s lifespan.

• Good digestive health can be achieved by increasing the content of dietary fibre. This also prevents constipation, which is common. When dietary fibre is added the energy density of the food is reduced without cutting volume.

The cells can be given extra help in their fight against oxidative stress through increased vitamins and trace elements, particularly antioxidants, such as vitamin E, vitamin C, green tea polyphenols and flavonoids.

Although home-prepared diets are an option for ageing dogs, as they can be fine-tuned based on the animal’s specific problems, it is important to remember that a mixture of meat, vegetables and rice is not a balanced diet, being particularly deficient in calcium and essential fatty acids. The veterinarian’s expertise should always be the owner’s starting point.

Some complete dry foods are specially formulated to meet the requirements of a dog based on its size and lifestage, which can be advantageous. The size and density of kibbles, for example, are adapted to the more fragile teeth of ageing dogs, while the very high digestibility of the raw ingredients helps prevent diarrhoea.

These top quality foods ensure an even better match with the individual dog’s requirements.

Diseases affecting ageing dogs


Advancements in veterinary medicine have significantly extended the life expectancy of dogs – and cats too – in recent years, especially in relation to better food and improved health. As a result, a new discipline has emerged in veterinary medicine. Geriatrics is the medical science of diseases associated with old age. It demands regular health checks to monitor the animal’s health in the final years of life. Some major functions and organs need to be monitored regularly to ensure that any problems are identified quickly and appropriate action implemented rapidly.

Behavioural problems


With age comes a reduction in the capacity for adaptation, which also applies to behaviour. Behavioural specialists have identified three main disorders that are likely to appear in old age.

Aggressiveness can be a problem in ageing dogs, which can be less patient and more aggressive, even resorting to biting. Physical disorders can be the cause, so the dog should be examined by a veterinarian. If the dog is deaf it may be surprised and simply defending itself. Similarly, if a dog has arthritis in its hips it may feel pain if it is lifted up. The dog’s natural reaction will be to bite in the area of the pain, which might lead it to biting the person’s hand. In fact these are physical and not behavioural disorders and should be treated as such.

A dog suffering from involutional depression gradually loses its social skills. It will start to defaecate or urinate in inappropriate places, no longer heed commands or will eat everything it can find. It can have problems sleeping or it may start howling for no apparent reason. Effective medical treatments are available.


Aggressiveness can be a problem in ageing dogs, which can be less patient and more
aggressive, even resorting to biting.


Ageing dogs may also be affected by dysthymic depression, which can include an inability to gauge the size of a passageway in relation to their own body. The dog will tend to want to force its way through and may be jammed for hours, growling and whining. Only one drug has been proven to be effective in the event of this disease.

A full check-up and appropriate treatment and management should be initiated in response to any apparent behavioural disorder in the older dog.

Heart failure

When an organ fails it is no longer able to do its work effectively. The dog will exhibit clinical signs that will worry the owner. In the event of heart failure, the dog will tire quickly and may cough. Depending on the part of the heart affected, it may also result in oedema (accumulation of fluid). This disease can be diagnosed early with regular monitoring of the heart function (auscultation, electrocardiogram, ultrasound), so that the dog can be treated with the appropriate medication and a diet can be initiated that supports heart function.

Kidney failure

The kidneys remove waste products, particularly urea, from the blood and excrete them via the urine. Chronic kidney failure can be defined as the gradual and irreversible loss of kidney functions: excretion, regulation and hormone production. It does
not become apparent until more than 75% of the nephrons (the functional units of the kidney) have disappeared, so diagnosis is always late in the progression of the disease.

The first clinical signs owners will notice are an increase in water intake (polydipsia) and increased urination (polyuria). If it drinks a lot, the dog may not be able hold its urine overnight and urinate in the house. It will often lose weight, firstly because the increased urea in the blood adversely affects its appetite, then because the disease increases the use of body protein. The veterinarian will base a diagnosis on the clinical signs described by the owner and the results of supplementary tests (measurements of the quantity of urea, creatinine, protein and some minerals in the blood).

If diagnosed early during regular check-ups, kidney disease can be treated with a combination of medication based on the clinical signs and a diet that supports kidney function. Limiting dietary phosphorus intake is vital as it is toxic for the kidneys, inducing hormone changes that can damage bones and kidneys. Urea formation also needs to be reduced through the moderate intake of proteins of high biological value. Weight and body condition (especially muscle mass) need to be regularly monitored in dogs suffering from kidney failure. The increased intake of omega- 3 essential fatty acids has also been shown to have a positive impact on failing kidney function. Complete nutritional foods are available specially formulated for dogs suffering from kidney disease with particular attention to high palatability to ensure the dog eats its food.

Diseases of the digestive tract

Plaque and periodontal disease are access routes for pathogens that can cause lung, heart, kidney or joint diseases, as stated above. Prepared food was long wrongly identified as the culprit in plaque formation and development of periodontal disease, but many recent studies have shown that dry kibbles are better at preventing dental plaque formation than wet food sold in cans or sachets. The latter tends to accumulate around the point where the tooth enters the gum, while kibbles have an abrasive effect on the teeth, which helps to keep them clean. Together with regular brushing, for which many products are now available from veterinarians, kibbles are the best way of preventing this problem. Some chewing treats can also help to improve the dog’s oral hygiene. Once tartar (calcified plaque) has built up on teeth, it will have to be removed by the veterinarian.

Constipation is a common problem among old dogs due to the slowing down of intestinal transit and the reduction in physical activity. This can be treated and prevented by giving the dog a diet with a higher fibre content. The administration of paraffin oil or laxatives should only be a temporary measure, unless advised and monitored by the veterinarian. Physical activity remains the best solution.


Uncontrolled cell development leads to the formation of cell masses. Depending on their location, they will have differing consequences. Malignant tumours can spread throughout the body, making treatment uncertain. As in human medicine, chemotherapy with drugs and radiotherapy are available and are advancing all the time. Weight loss must be minimised, especially loss of muscle mass, as this helps the prognosis of the patient. Diet is a fully-fledged part of cancer treatment. The goal is to feed the dog and not the tumour, which is achieved by using very high quality ingredients and adjusting the formulation of the food.


Owners can begin combating the effects of ageing in dogs when the puppy is still very young, by adopting preventive health and dietary measures.


In conclusion, owners can begin combating the effects of ageing in dogs when the puppy is still very young, by adopting preventive health and dietary measures. As it grows older the dog should receive regular check-ups so that any problems can be diagnosed early and treated as soon as possible. Monitoring and maintenance of a good body condition is a priority. Both obesity and muscle wastage must be avoided. A diet that takes full account of the individual dog’s nutritional needs will ensure that this is achieved.

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From maturity to old age
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