Approximately 44% of dogs and cats in the United States are 6 years or older, and about one-third of these pets are 11 years
or older.1 Naturally, many of these patients are cherished family members whose owners are committed to providing them with the best
of care, including optimal nutrition.
When are pets considered mature adults and when are they "seniors"?
The wide range in size and body type among dog breeds can result in significantly different life spans. According to one reference,
individuals of giant breeds were classified as seniors when older than 7 years, and large breeds were classified as seniors
when older than 9 years, compared with 10 years for medium-sized breeds and 12 years for small and toy breeds.2 Cats may be considered mature adults or middle-aged when 7 years and older, seniors when 11 years and older, and geriatric
when 15 years and older.3 It is important to note that age-related changes may occur before signs of aging are apparent to an owner. For this reason,
specific nutrition for older pets should be recommended earlier than when pets are typically considered to be senior, and,
for dogs, breed size should be considered. For cats and small-, toy-, and medium-sized dog breeds, age-related changes may
start occurring during the mature adult years, and this third midlife stage begins around the age of 7. For giant- and large-sized
breeds, the mature adult life stage begins earlier, at about 5 to 6 years of age, because of their shorter life spans.
Nutritional needs of senior pets
Aging pets have reduced activity levels, a decrease in lean muscle mass, and an increase in the proportion of body fat. Some
older pets have hearing loss and decreased visual acuity. Changes in the senses of smell and taste can reduce interest in
food and cause weight loss. Skeletal and organ changes develop in some pets — mobility problems, periodontal disease, compromised
renal or heart function, cognitive dysfunction, and neoplastic disease. Age-related changes can alter daily energy needs,
change the amounts and type of protein and fat needed, and modify mineral and vitamin requirements.
Most older pets have reduced daily energy needs. However, it is important to keep in mind that energy needs are influenced
by individual temperament and activity level, degenerative disease, and the ability to digest and assimilate nutrients. Thus,
caloric intake should be carefully monitored in older pets.
High-quality dietary fat makes food palatable. Palatability is especially important in older pets with a diminished sense
of smell or taste or a reluctance to eat. However, adjusting the amount of fat in the diet may benefit both mature adult and
senior dogs and cats that are at risk of weight gain. Pets entering the mature adult life stage may require less fat than
dogs and cats in the adult life stage do, and pets transitioning from the mature adult life stage to the senior life stage
may require slightly more fat.
Contrary to persistent popular belief, healthy older dogs and cats do not benefit from reduced dietary protein. Older pets
require high-quality protein at slightly higher concentrations than the levels in most adult maintenance diets.4,5 Sufficient dietary protein with an optimal balance of amino acids is essential to support a healthy body condition, to prevent
loss of muscle mass, and to support a healthy immune system. This is especially important for cats that have a naturally high
protein requirement and that do not tolerate low-protein diets.
Mature adult and senior pets may experience problems with glucose metabolism. Choosing a diet that blunts the postprandial
blood glucose surge can improve glycemic control. Thus, the type of starch in the diet is important. Studies have shown that
feeding dogs sorghum or barley as starch sources lowers the blood glucose response, when compared with feeding dogs food that
contains wheat or rice.6 Similar results have been reported in cats.7
Senior pets can be prone to digestive challenges. Dogs and cats should be fed a diet that contains moderate levels of a fiber
such as beet pulp, which includes both fermentable and nonfermentable components. Another type of beneficial fiber called
fructooligosaccharides (FOS) works as a prebiotic by promoting the growth of beneficial bacteria and inhibiting nonbeneficial
bacteria in the digestive tract.8
Vitamins and minerals:
Older animals require the same vitamins and minerals as young adults. However, vitamins that have antioxidant functions, such
as vitamin E and beta-carotene, are especially important for senior animals.
The veterinary team's role
A 2011 survey of more than 1,200 senior dog owners found that only 30% of owners who were feeding a senior dog food based
their choice on a veterinarian's recommendation.9 Owner misperceptions about senior pets' needs and the abundance of over-the-counter senior pet foods mean that owners need
your team's guidance. This dietary counseling need not take extra time or effort and can be seamlessly integrated into your
clinic's regular wellness appointments.
When advising clients, your primary objectives are to educate them about the nutrient and energy needs of senior pets and
to help them select a food that is best formulated to meet the unique needs of an individual pet. Your team's input about
senior pet diets will contribute to the pets' long-term health and vitality.
References are available