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Useful information about the needs of cats and dogs with nutritionally sensitive health conditions.

Abnormal Body Condition

Sarcopenia in Dogs and Cats

Sarcopenia is the age-related loss of lean body mass (LBM) that occurs unrelated to disease. With age, the rate of protein catabolism often exceeds protein synthesis. This imbalance leads to progressive loss of lean body mass with loss of strength, diminished quality of life, and shorter life span.1  Although this condition occurs in both dogs and cats, it seems to be more clinically significant in cats. 

There is no single known cause of sarcopenia. The multifactorial etiology of this slowly progressive condition includes inadequate intake of protein or calories, altered protein turnover with decreased protein synthesis and increased protein catabolism, chronic increase in inflammatory cytokinesmitochondrial dysfunction, and increased oxidative stress.1,2  

While nutrition cannot prevent sarcopenia, the earlier this condition is identified the more opportunity there is to help delay age-related changes in body weight and body composition of older pets. 

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Key Messages

  • Routine nutritional assessments that include body weight, body condition, and muscle condition scoring, can aid in earlier identification of LBM loss. 
    • Tracking only body weight may miss losses of lean body mass that may be masked by increased body fat.2,3  
  • Ensure dietary protein is adequate to minimize LBM loss, and only restrict protein if medically essential. 
    • Older dogs and cats have higher protein needs than younger animals.4-6 
    • Inadequate protein intake increases the rate of loss of LBM in aging dogs, while abundant protein slows the loss.7  
    • Guidelines suggest about 2.55 gram of protein/kg body weight for healthy adult dogs and about 5 grams/kg body weight in healthy adult cats while also assuring adequate calorie intake.8  
    • Specific amino acids may play a role in reducing loss of LBM. 
      • For example, one study showed that increasing dietary lysine, independent of total protein, helped reduce loss of LBM in aging cats.9 
  • Ensure calorie intake is adequate, keeping in mind that older dogs often need fewer calories while older cats may need more calories to meet their nutritional needs.8 
    • Calorie density varies widely among pet foods—from more than 600 kcal/cup to  less than 250 kcal/cup. Ensure that any weight loss is not the unintended result of switching to a lower calorie food.3 
    • Changes in appetite and/or decreased food intake are common in senior pets. 
      • Strategies to keep senior pets eating include feeding meals more frequently or using flavor enhancers. 
        • Avoid flavor additives that are high in sodium for pets with heart failure, or high in phosphorus for pets with kidney disease.1 
  • Fish oil supplementation, high in the long-chain omega-3 fatty acids EPA and DHA, can decrease inflammatory cytokine production and improve food intake.10 
    • Flax seed oil or other plant-based omega-3 fatty acids are ineffective sources of EPA and DHA for these species.11 
Did you know fact highlight

Preserving LBM in aging cats enhances longevity:  A longitudinal study of aging showed that non-obese cats had a 2% increased chance of survival for every 10-gram increase in LBM. 12 

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Evaluating Your Cat’s Body Condition

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Evaluating Your Dog’s Body Condition

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

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  1. Freeman, L. M. (2012). Cachexia and sarcopenia: Emerging syndromes of importance in dogs and cats. Journal of Veterinary Internal Medicine, 26, 3–17. 
  2. Laflamme, D. P. (2020). Understanding the nutritional needs of healthy cats and those with diet-sensitive conditions. Veterinary Clinics of North America: Small Animal Practice, 50(5), 905–924. doi: 10.1016/j.cvsm.2020.05.001 
  3. Hutchinson, D., Freeman, L. M., Schreiner, K. E., & Terkla, D. G. (2011). Survey of opinions about nutritional requirements of senior dogs and analysis of nutrient profiles of commercially available diets for senior dogs. International Journal of Applied Research in Veterinary Medicine, 9(1), 68–79.  
  4. Laflamme, D. P., & Hannah, S. S. (2013). Discrepancy between use of lean body mass or nitrogen balance to determine protein requirements for adult cats. Journal of Feline Medicine and Surgery, 15(8), 691–697. 
  5. Perez-Camargo, G., Patil, A. R., & Cupp, C. J. (2004). Body composition changes in aging cats. Compendium on Continuing Education for the Practicing Veterinarian, 26(Suppl 2A), 71.  
  6. Wannemacher, R. W., &  McCoy, J. R. (1966). Determination of optimal dietary protein requirements of young and old dogs. Journal of Nutrition, 88(1), 66–74. 
  7. Kealy, R. D. (1999). Factors influencing lean body mass in aging dogs. Compendium on Continuing Education for the Practicing Veterinarian, 2(11K), 34–37.  
  8. Churchill, J. A., & Eirmann, L. (2021). Senior pet nutrition and management. Veterinary Clinics of North America: Small Animal Practice, 51(3), 635–651. doi: 10.1016/j.cvsm.2021.01.004 
  9. Frantz, N. Z., Yamka, R. M., & Friesen, K. G. (2007). The effect of diet and lysine: calorie ratio on body composition and kidney health in geriatric cats. International Journal of Applied Research in Veterinary Medicine, 5(1), 25–36. 
  10. Freeman, L. M., Rush, J. E., Kehayias, J. J., Ross, J. N., Jr, Meydani, S. N., Brown, D. J., Dolnikowski, G. G., Marmor, B. N., White, M. E., Dinarello, C. A., & Roubenoff, R. (1998). Nutritional alterations and the effect of fish oil supplementation in dogs with heart failure. Journal of Veterinary Internal Medicine, 12(6), 440–448. doi: 10.1111/j.1939-1676.1998.tb02148.x 
  11. Bauer, J. E. (2007). Responses of dogs to dietary omega-3 fatty acids. Journal of the American Veterinary Medical Association, 231(11), 1657–1661. doi: 10.2460/javma.231.11.1657 
  12. Cupp, C. J., Kerr, W. W., Jean-Philippe, C., Patil, A. R., & Perez-Camargo, G. (2008). The role of nutritional interventions in the longevity and maintenance of long-term health in aging cats. International Journal of Applied Research in Veterinary Medicine, 6(2), 69–81.