Practice Scenario

Meet Dewey, a senior cat that has lost weight.

Get to know DEWEY

A 13-year-old, neutered male cat

  • Dewey is an indoor cat presented for gradual weight loss.
  • Owner has not noticed a change in Dewey’s appetite. However, she has 3 cats and group feeds them an adult dry cat food ad libitum plus a “small amount” of canned food occasionally as a treat. She is not sure if Dewey is drinking or urinating more.
  • Dewey has a body condition score of 3/9, weighs 4.3 kg (9.5 pounds), and has moderate muscle loss. Dewey has not been examined in over 2 years. His last recorded body condition score was 5/9 when he weighed 5.4 kg (almost 12 pounds).
  • On exam, Dewey is quiet, but responsive. Mucous membranes are somewhat dry with a normal capillary refill time. Although he is purring, heart and lung sounds appear normal. He exhibits no pain on abdominal palpation. His kidneys feel slightly small.

Renal & Urinary Disorders

Chronic Kidney Disease (CKD) in Cats

Chronic kidney disease is diagnosed in about 1 in 3 cats over 10 years of age.1,2 In cats, although there are breed-related causes of CKD, such as polycystic kidney disease in Persian cats, the cause is usually idiopathic.3 Based on clinical exams and laboratory tests, CKD in cats can be "staged" and managed with a combination of medical treatments and therapeutic diets, according to guidelines developed by the International Renal Interest Society (IRIS).

Nutritional management for cats with CKD has four general aims: to maintain adequate nutrition; mitigate clinical consequences of CKD, including signs of uremia; address the changes in homeostasis that result from inadequate kidney function; slow disease progression and prolong lifespan.4 Although the disease is progressive, individualized medical and nutritional management can help many cats live with CKD for years.5 

feline kidneys icon

Key Messages

  • Serial evaluations of nutritional status and a patient-tailored nutritional plan are crucial to care.6 
    • Assessing muscle mass is particularly important because creatinine may be misleadingly low in patients with reduced muscle mass.7  
    • Loss of lean body mass is associated with increased mortality in aging and in CKD.5,7 
  • Ensure adequate calorie intake. If energy needs are not met, catabolism of body tissues occurs, leading to losses of lean body mass and increasing risk of morbidity and mortality in cats with CKD.8  
    • Avoid unnecessary diet changes in ill cats to reduce the risk of food aversions leading to refusal of specific diets. When diet change is needed, do so slowly and while cat is feeling well.6  
  • Key nutritional factors include phosphorus, protein, potassium, omega-3 fatty acids and alkalinizing buffers. Therapeutic renal diets favor better clinical outcomes (longer survival and fewer uremic crises) than adult maintenance diets for cats with moderate to severe CKD.4,9-12   
    • Phosphorus regulation is disrupted in CKD and hyperphosphatemia, as well as elevations in parathyroid hormone (PTH) or fibroblast growth factor 23 (FGF23), contribute to ongoing damage in the face of existing kidney disease. Manage serum phosphate levels based on the IRIS stage with dietary phosphorus restriction and phosphate binders.4 
  • Cats require high levels of protein in their diets and senior cats may need even more. The goal is to avoid deficiency that can contribute to loss of lean body mass, yet also avoid excessive intake.6  
    • Based on the available evidence, protein restriction per se is not warranted in cats with CKD.10  
    • Maintaining higher protein levels in early stages of CKD may help preserve lean body mass.13-15  
    • Moderate protein restriction in later stages may help reduce accumulation of nitrogenous wastes.4  
  • Maintaining adequate potassium is critical to normal renal function, and low potassium can cause or worsen CKD.6  
    • Most therapeutic renal diets are supplemented with potassium, but blood levels should be routinely monitored in cats with CKD.16-19  
  • Omega-3 fatty acids from fish oil are often recommended for cats with CKD.10,11, 20  
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Although dietary sodium restriction is recommended for people with CKD, evidence in cats suggests not only is this unnecessary but also that excessive restriction can be harmful.2,10

Related Tools and Content:

CHRONIC KIDNEY DISEASE IN CATS: Nutritional Management

Nutritional interventions tailored to the individual cat with CKD can play a key role in slowing disease progression, reducing signs of uremia, addressing homeostatic changes resulting from CKD, and improving quality of life as well as life span.

View Monograph 20+ minutes

Taking a Good Diet History

The only way to know what each patient really eats is to ask ꟷ and document the information in the medical record.

View Brief 1 min to 5 min

How to Perform a Body Condition Assessment - Cat

Assess a cat's Body Condition Score in just 3 simple steps.​

View Video 1 min to 5 min

Use Muscle Condition Scoring to Detect Muscle Loss in Patients

Muscle condition scoring is a hands-on method for evaluating lean body mass that can be used as part of nutritional assessments.

View Brief 1 min to 5 min

To Share With Pet Owner:

Evaluating Your Cat’s Body Condition

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

View Video 1 min to 5 min

References

  1. Lulich, J. P., Osborne, C. A., O’Brien T. D., & Polzin, D. J. (1992). Feline renal failure: Questions, answers, questions. Compendium on Continuing Education for the Practicing Veterinarian, 14, 127–152.
  2. Sparkes, A. H., Caney, S., Chalhoub, S., Elliott, J., Finch, N., Gajanayake, I., Langston, C., Lefebvre, H. P., White, J., & Quimby, J. (2016). ISFM consensus guidelines on the diagnosis and management of feline chronic kidney disease. Journal of Feline Medicine and Surgery, 18(3), 219–239. doi: 10.1177/1098612X16631234
  3. Brown, C. A., Elliott, J., Schmiedt, C. W., & Brown, S. A. (2016). Chronic kidney disease in aged cats: Clinical features, morphology, and proposed pathogeneses. Veterinary Pathology, 53(2), 309–326. doi: 10.1177/0300985815622975
  4. International Renal Interest Society (IRIS). (2019). IRIS staging of CKD (modified 2019). http://www.iris-kidney.com/pdf/IRIS_Staging_of_CKD_modified_2019.pdf​
  5. Boyd, L. M., Langston, C., Thompson, K., Zivin, K., & Imanishi, M. (2008). Survival in cats with naturally occurring chronic kidney disease (2000–2002). Journal of Veterinary Internal Medicine, 22(5), 1111–1117. doi: 10.1111/j.1939-1676.2008.0163.x​
  6. Quimby, J. M. (2016). Update on medical management of clinical manifestations of chronic kidney disease. Veterinary Clinics of North America: Small Animal Practice, 46(6), 1163–1181. doi: 10.1016/j.cvsm.2016.06.004
  7. Freeman, L. M., Lachaud, M. P., Matthews, S., Rhodes, L., & Zollers, B. (2016). Evaluation of weight loss over time in cats with chronic kidney disease. Journal of Veterinary Internal Medicine, 30(5), 1661–1666. doi: 10.1111/jvim.14561
  8. Larsen, J. A. (2016). Controversies in veterinary nephrology: Differing viewpoints: Role of dietary protein in the management of feline chronic kidney disease. Veterinary Clinics of North America: Small Animal Practice, 46(6), 1095–1098. doi: 10.1016/j.cvsm.2016.06.012
  9. Elliott, J., Rawlings, J. M., Markwell, P. J., & Barber, P. J. (2000). Survival of cats with naturally occurring chronic renal failure: Effect of dietary management. Journal of Small Animal Practice, 41(6), 235–242. doi: 10.1111/j.1748-5827.2000.tb03932.x
  10. Laflamme, D., Backus, R., Brown, S., Butterwick, R., Czarnecki-Maulden, G., Elliott, J., Fascetti, A., & Polzin, D. (2020). A review of phosphorus homeostasis and the impact of different types and amounts of dietary phosphate on metabolism and renal health in cats. Journal of Veterinary Internal Medicine, 34(6), 2187–2196. doi: 10.1111/jvim.15961
  11. Plantinga, E. A., Everts, H., Kastelein, A. M., & Beynen, A. C. (2005). Retrospective study of the survival of cats with acquired chronic renal insufficiency offered different commercial diets. Veterinary Record, 157(7), 185–187. doi: 10.1136/vr.157.7.185
  12. Ross, S. J., Osborne, C. A., Kirk, C. A., Lowry, S. R., Koehler, L. A., & Polzin, D. J. (2006). Clinical evaluation of dietary modification for treatment of spontaneous chronic kidney disease in cats. Journal of the American Veterinary Medical Association, 229(6), 949–957. doi: 10.2460/javma.229.6.949
  13. Nguyen, P., Leray, V., Dumon, H., Martin, L., Siliart, B., Diez, M., & Biourge, V. (2004). High protein intake affects lean body mass but not energy expenditure in nonobese neutered cats. Journal of Nutrition, 134(8 Suppl), 2084S–2086S. doi: 10.1093/jn/134.8.2084S
  14. Noguiera, A., Pires, M., & Oliveira, P. (2017). Pathophysiological mechanisms of renal fibrosis: A review of animal models and therapeutic strategies. in vivo, 31(1): 1–22.
  15. Perez-Camargo, G. (2004). Cat nutrition: What’s new in the old? Compendium on Continuing Education for the Practicing Veterinarian, 26(S2A), 5–10.
  16. Buranakarl, C., Mathur, S., & Brown, S. A. (2004). Effects of dietary sodium chloride intake on renal function and blood pressure in cats with normal and reduced renal function. American Journal of Veterinary Research, 65(5), 620–627. doi: 10.2460/ajvr.2004.65.620​
  17. DiBartola, S. P., Buffington, C. A., Chew, D. J., McLoughlin, M. A., & Sparks, R. A. (1993). Development of chronic renal disease in cats fed a commercial diet. Journal of the American Veterinary Medical Association, 202(5), 744–751.
  18. Dow, S. W., Fettman, M. J., LeCouteur, R. A., & Hamar, D. W. (1987). Potassium depletion in cats: Renal and dietary influences. Journal of the American Veterinary Medical Association, 191(12), 1569–1575.
  19. Theisen, S. K., DiBartola, S. P., Radin, M. J., Chew, D. J., Buffington, C. A., & Dow, S. W. (1997). Muscle potassium content and potassium gluconate supplementation in normokalemic cats with naturally occurring chronic renal failure. Journal of Veterinary Internal Medicine, 11(4), 212–217. doi: 10.1111/j.1939-1676.1997.tb00093.x
  20. Priante, G., Musacchio, E., Valvason, C., Clari, G., Bordin, L., Sartori, L., & Baggio, B. (2013). Further insights about the beneficial effects of n-3 fatty acids in the early molecular events of renal fibrosis in vitro. Journal of Nephrology, 26(4), 652–659. doi: 10.5301/jn.5000193