Changes in the diet of dogs and cats according to age 

How pets’ nutritional requirements vary as they grow. Recommendations for proper nutritional management at each stage.
Just as a pet’s organism changes over the years, the same happens with its nutritional requirements throughout its life.
For this reason, their diet must be modified at each stage to adjust to these different needs and cover them adequately.
The timeline of the life of a dog or a cat can be divided into three main stages or phases: growth, adulthood and aging or maturity, each of them with different nutritional requirements.

The pets’ diet must be adjusted to body changes throughout life

Growth: nutrients and energy

The high demand for nutrients and energy that puppies and kittens have during this stage exceeds those of any other period of their lives, except lactation. After weaning, and during the first six months of life, they go through the period of greatest body growth. Most dog breeds reach 50 percent of their adult weight in the first four to five months of life, which is the first stage of growth. From that moment, and due to the wide differences in body size that exist between the different canine breeds, the growth period to adulthood presents differences in speed and duration. While puppies of small and medium breeds (less than 30 kg of adult body weight) should receive a specific diet for this stage up to one year of life, those of large and giant breeds need to continue with this scheme until they are at least 18 months of age. In puppies of these sizes it is also very important to regulate the caloric intake of the diet so as not to hasten development to a maximum growth rate, which could cause osteoarticular disorders in large dogs.

The high caloric requirements of puppies and kittens during the first stage of growth decrease as they grow. Upon reaching 80 percent of adult body weight, they need only 20 percent more energy than that required by the same adult specimen.

Puppies and kittens have a higher demand for protein than adults due to the need for this essential nutrient to form part of the structure of developing tissues. But the protein contribution must not only be higher in quantity but also in quality, or biological value. In other words, the diet of puppies and kittens must contain highly digestible proteins, mostly of animal origin, which provide all the essential amino acids that the body requires for normal growth and development. Some of the sources of better nutritional quality in this regard are powdered whole egg, bovine plasma and chicken meat or flour, among others.

The contribution of calcium and phosphorus in the diet of puppies and kittens is very important both in quantity and in the proper balance between both minerals. More than 99% of the body’s calcium is found in the bones. It is easy to understand then that both the deficiency and the excess of this mineral, added to an inadequate supply ratio with respect to phosphorus, can cause bone disorders during growth.

Docosahexaenoic acid (DHA) plays a very important role in the proper development of the brain and the retina in puppies and kittens, both in the last third of their gestation and in the first months of life. After weaning, puppies’ brains continue to develop, acquiring 90 percent of their adult brain mass only at 3 months of age. Hence the importance of including DHA in the nutrition of the growing dog as it improves its learning capacity, memory and vision.

To help prevent possible digestive overload disorders, particularly in “gluttonous” puppies with greedy feeding behavior, it is advisable to distribute the administration of the total daily ration in at least 3 to 4 servings.

Adults in maintenance: control calories

At the end of the growth stage and reach adulthood, most dogs and cats enter a stage that is normally known as maintenance. This qualification refers to that of a pet that has a certain level of daily physical activity, or that is going through a certain physiological stage, which doesn’t merit higher nutritional or caloric requirements. In other words, they aren’t working animals, such as dogs that collaborate with the Security Forces, in rural tasks or in sport hunting, among others. Neither is it a question of reproductive males during the service period or of pregnant or lactating females. For this reason, in adult pets in maintenance it’s very important to control that there are no excesses in daily caloric consumption to avoid health problems related to overweight or obesity. In this sense, consultation with the veterinarian is the most convenient way to adjust the size of the food ration in each particular case.

As the body of the adult pet no longer has the need for the high nutritional demands of development, the balanced food formulated for this stage lowers the contribution of proteins, fat, vitamins and minerals, in line with the recommendations of reference organisms in animal nutrition, such as AAFCO, Fediaf or NRC.

Regarding the management of the administration of food in dogs in the adult stage, it’s recommended that the fractionation of the ration be two daily intakes.

Pregnant and lactating adults: the highest requirements

When the female dog or cat is in the reproductive stage, their nutritional management is totally different from that of maintenance. Pregnancy, together with lactation, constitute the two physiological stages that demand the highest nutritional requirements from the body. During a few weeks their protein needs increase to almost 70 percent, energy needs increase to 60 percent in large litters, the same as calcium and phosphorus.

To meet these important demands, it is convenient that the mother’s diet comes from   a balanced with good digestibility, of super Premium or premium quality, with high energy density and with the balanced contribution of all essential nutrients. For such  reason, the indication of nutritional management in this stage of the female in pregnancy or lactation is to supply balanced formulated for puppies or kittens, as the case may be. Regarding the form of administration of food during lactation, it is recommended that it be freely available to the female, that is, that she consume  the daily amount of balanced that her body requires.  Unless specific veterinary indication, and as long as the aforementioned recommendations are followed, the use of nutritional supplements at this stage is discouraged.

Mature stage: preventive nutrition

After approximately seven years of life, the organism of adult dogs and cats begins to present alterations typical of mature or senior age that merit a new adjustment in their diet to help reinforce their health.

Most pets of this age decrease the intensity of their physical activity so the daily caloric intake should be reduced to avoid becoming overweight. This energy reduction also contributes to prolonging the life of senior pets. A study carried out on Labrador Retriever dogs throughout their lives concluded that those animals that consumed 25 percent less of the same food daily compared to their control companions, of the same gender and age, but who had a freely available diet , increased their longevity by 20 percent compared to the latter.

A specific diet for mature pets can help achieve a better quality of life at this stage

As a consequence of the natural wear and tear that occurs in the joints of senior pets, osteoarthritis can occur with manifestations of pain and reduced mobility.  In order not to overload the damaged joints and help regain joint functionality, it is therefore advisable to reduce the caloric intake of the diet.  The use of balanced products that provide chondroprotective additives, such as chondroitin sulfate, glucosamine chloride and organic manganese, are also helpful for the nutritional management of this problem.

The protein intake in senior diets must also adjust to changes at that age. To compensate for the loss of muscle mass typical of this stage, it is necessary to increase the supply of proteins, but these must be of high biological value and good digestibility so as not to affect kidney function.

The cardiovascular system of mature pets can show signs of aging. For this reason, the adequate contribution in their diet of nutrients such as taurine and L-carnitine, together with the reduction of sodium and the reinforcement of essential omega 3 fatty acids, contributes to taking care of the heart.

In the mature stage most of the organs of dogs and cats become more vulnerable to cell damage. Immune defenses begin to  be less effective in their protective function, with a greater predisposition to the development of infections and autoimmune diseases. To strengthen the immune system of older pets, it is important that their diet contains natural antioxidant agents such as vitamins A, C and E, organic selenium, lutein, polyphenols, tocopherols and omega 3 essential fatty acids, among others.

The passage of time also affects the central nervous system of pets, with neurological impairments that negatively affect different functions such as memory, attention span, learning and coordination of movements. The contribution of DHA to the senior diet contributes to the nutritional management of these age-related problems.

Throughout their lives, cats and dogs change their nutritional requirements. Changing the diet, using the type of balanced food that best suits the needs of each stage, is very important to help take care of the health and well-being of these pets.

M.V. Julio Bernal

Dpto. Técnico GEPSA Petfoods