Practice Scenario

a black senior labrador retriever

Meet RUSTY

A 12-year-old, neutered-male, Labrador Retriever

  • Rusty is at the clinic today for a semiannual senior wellness examination and possibly blood and urine tests.
  • His owner reports that Rusty is generally healthy. However, Rusty is not as active as he used to be, sleeps less at night and occasionally seems confused.
  • Rusty eats a variety of different commercial “senior” diets. His owner would like to know if there is any difference among senior dog foods and if there is one that would be better for Rusty at this time.

Senior Dog

Feeding Senior Dogs

Aging is not a disease, although it is often associated with health problems. Nutrition can play a powerful role to help maintain health and optimal body condition, address age-related health issues before they occur, reduce the risk of weight gain or obesity, and possibly add more quality and longevity to a dog’s life. 

senior Weimaraner

Key Messages


  • Every dog ages at a different rate that varies by breed and body size, even though most dogs are considered "senior" at around 7 years of age. 
    • While ultimately determined by genetics, aging can be influenced by nutrition, activity, health problems and environment. 
Dog Breed Size Age Considered Senior
Toy  9 years 
Small  8 years 
Medium  7 years 
Large  6 years 
Giant  5 years 
Adapted from Nestlé Purina PetCare Communication Principles for Europe, Middle East & North Africa. (2015). p. 14. 
  • Age-related changes inside an aging dog's body may be occurring before external signs or behaviors are seen. These changes may include: 
    • Less efficient use of glucose for energy by the aging brain, which can affect cognitive health (i.e., memory and learning). Mild cognitive impairment has been reported in dogs as young as 6 years old. 
    • A slower metabolism and lower activity level that together result in lower energy (calorie) needs and increase the potential for excess weight gain unless an adjustment in the type or amount of food is made. Excess weight places additional stress on aging joints, increasing the risk of osteoarthritis. 
    • Less efficient protein metabolism, which may result in loss of lean body mass (e.g., muscle). Less lean body mass contributes to a slower metabolism and may increase the risk for weight gain. 
  • A good time to discuss the benefits of senior diets is when a dog reaches about 7 years of age because targeted nutrition can proactively address some age-related changes. There are no established nutrient profiles for the senior dog life stage. However, several nutritional interventions have been shown to be beneficial: 
    • Purina studies show dietary medium-chain triglycerides (MCTs) sourced from enhanced botanical oils can provide an alternative energy source for brain cells that may help support cognitive function in dogs as they age. 
    • Increased levels of high-quality protein and reduced levels of fat and calories can help maintain optimal body condition and lean muscle mass. 
    • Eicosapentaenoic acid (EPA), an omega-3 fatty acid found in fish oil, and glucosamine from natural sources help support joint health and mobility. Omega-3 fatty acids also may help reduce inflammation. 
    • Antioxidants (e.g., vitamins C and E) and probiotics help support a healthy immune system, while probiotics and prebiotic fiber help promote healthy digestion. 
  • Aging dogs should be fed to maintain ideal body condition and preserve lean body mass for optimal health and longevity. 
conversation starter background image

"Senior dogs tend to gain unwanted weight, so our goal is to keep [dog’s name] in ideal body condition. It is easy to regularly monitor [him/her] at home ꟷ simply check [his/her] waist, tummy tuck and feel the ribs. Feeding a senior dog food that is lower in calories and fat while providing increased levels of protein and antioxidants may help keep your dog in ideal body condition." 

To Share With Pet Owner:

DISHAA Assessment Tool

A useful tool to monitor cognitive function in dogs.​

View Tool 1 min to 5 min

Protein and Senior Pets

Protein is a key nutrient for dogs and cats and a source of amino acids, the 'building blocks' used to build new proteins in the body. Irrespective of the pet’s age, protein plays many important roles in the body.

View Hot Topic 6 min to 10 min

Benefits of Healthy Weight

Although there are many benefits to maintaining a healthy weight in pets, many owners do not understand what a healthy weight is or the benefits for pets.

View Hot Topic 6 min to 10 min

Canine Body Condition System Sheet

A visual aid to the Purina Body Condition Score System for dogs.​

View Tool 1 min to 5 min

Evaluating Your Dog’s Body Condition

Assess your dog's Body Condition in just 3 simple steps.​

View Video 1 min to 5 min

Additional Resources

Debraekeleer, J., Gross, K. L., & Zicker, S. C. (2010). Feeding mature adult dogs: Middle aged and older. In M.S. Hand, C. D. Thatcher, R. L. Remillard, P. Roudebush, & B. J. Novotny (Eds.). Small animal clinical nutrition (5th ed., pp. 273─280). Mark Morris Institute. 

Kealy, R. D., Lawler, D. F., Ballam, J. M., Lust, G., Smith, G. K., Biery, D. N., & Olsson, S. E. (1997). Five-year longitudinal study on limited food consumption and development of osteoarthritis in coxofemoral joints of dogs. Journal of the American Veterinary Medical Association, 210(2), 222─225. 

Kealy, R. D., Lawler, D. F., Ballam, J. M., Mantz, S. L., Biery, D. N., Greeley, E. H., Lust, G., Segre, M., Smith, G. K., & Stowe, H. D. (2002). Effects of diet restriction on life span and age-related changes in dogs. Journal of the American Veterinary Medical Association, 220(9), 1315─1320. doi: 10.2460/javma.2002.220.1315 

Laflamme, D. P., Martineau, B., & Jones, W. (2000). Effect of age on maintenance energy requirements and apparent digestibility of canine diets. Compendium of Continuing Education for the Practicing Veterinarian, 22(Suppl 9A), 113. 

Pan, Y., Larson, B., Araujo, J. A., Lau, W., de Rivera, C., Santana, R., Gore, A., & Milgram, N. W. (2010). Dietary supplementation with medium-chain TAG has long-lasting cognition-enhancing effects in aged dogs. British Journal of Nutrition, 103(12), 1746─1754. doi: 10.1017/S0007114510000097 

Pan, Y., Kennedy, A. D., Jönsson, T. J., & Milgram, N. W. (2018). Cognitive enhancement in old dogs from dietary supplementation with a nutrient blend containing arginine, antioxidants, B vitamins and fish oil. British Journal of Nutrition, 119(3), 349─358. doi: 10.1017/S0007114517003464 

Smith, G. K., Paster, E. R., Powers, M. Y., Lawler, D. F., Biery, D. N., Shofer, F. S., McKelvie, P. J., & Kealy, R. D. (2006). Lifelong diet restriction and radiographic evidence of osteoarthritis of the hip joint in dogs. Journal of the American Veterinary Medical Association, 229(5), 690─693. doi: 10.2460/javma.229.5.690