Senior dogs and cats need a low-protein diet.

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Myth or Fact? Senior Pets and Protein

Senior dogs and cats need a low-protein
diet to protect against kidney disease.

It's a myth

Years ago, lower protein levels for senior pet diets were recommended as a way to avoid potential kidney damage. Many consumers still believe that as their dogs and cats age, they should be fed diets with less protein.

The facts

Evidence shows that the protein levels in complete and balanced diets do not adversely affect the kidney function of healthy older pets.1

  • The old myth was based on rodent research done in the 1940s that has since been disproven.
  • More recent studies have looked at dietary protein in both healthy older dogs and in dogs with kidney failure. These studies have confirmed that protein does not adversely affect the kidneys.2,3
  • Phosphorus restriction, rather than protein restriction, is important once dogs or cats develop kidney disease.

Senior dogs and cats have a greater need for protein than young adult pets. 4,5

  • Protein requirements actually increase by about 50% in older dogs, while their calorie needs tend to decrease.
50% More Protein
  • Older cats also need more protein than their younger counterparts.
  • Because older pets metabolize protein less efficiently, they can benefit from a diet with ample supplies of high-quality protein.
  • Increased protein can actually help slow age-related loss of lean body mass and support a healthy immune system.


Contrary to popular belief, a diet rich in protein may be beneficial for aging pets. There is no medical evidence indicating that a high-protein diet leads to kidney damage in dogs or cats.

1. Laflamme DP. Pet food safety: dietary protein. Topics Comp Anim Med. 2008;23(3):154–157.
2. Kealy RD. Factors influencing lean body mass in aging dogs. Proceedings, 1998 Purina Nutrition Forum. Comp Cont Educ Pract Vet 1999;21(11 suppl):34–37.
3. Finco DR, Brown SA, Crowell WA, et al. Effects of aging and dietary protein intake on uninephrectomized geriatric dogs. Am J Vet Res. 1994;55(9):1282–1290.
4. Wannemacher RW Jr, McCoy JR. Determination of optimal dietary protein requirements of young and old dogs. J Nutr. 1966;88(1):66–74.
5. Peterson ME. Optimal protein requirements of older cats and cats with hyperthyroidism. November 7, 2011. for-older.html. Accessed May 1, 2013.