06About feline chronic kidney disease

What is chronic kidney disease (CKD)?

  • Definition of CKD: Presence of structural or functional abnormalities of one or both kidneys that have been present for an extended period.
  • It is the most frequent cause of death in cats aged over five years. Around 30-40% of cats over the age of 10 are said to suffer from CKD1.
  • Tubulointerstitial fibrosis is the lesion best correlated with severity of CKD2,3.
  • Tubulointerstitial fibrosis both initiate and perpetuate chronic kidney inflammation, hypoxia, and reduced blood flow, ultimately contributing to the irreversible progression of CKD4,5.

Changes in kidney structure


Histology (HE stain*)

Kidney of a healthy cat

Kidney of a cat with CKD

Tubulointerstitial fibrosis and inflammation is commonly found in kidney of cats with CKD.
*HE Stain: Hematoxylin and Eosin stain

Material courtesy of Professor Kenji Ochiai,
Department of Veterinary Pathology,
Faculty of Agriculture, Iwate University

Transmission electron microscopy image

Kidney of a healthy rat

Kidney of a nephritis induction model rat

There is marked decrease in the capillary network.
Reprinted from Prostaglandins & other Lipid Mediators 112, Yasufumi Goto, Shinichi Yamaguchi, Mitsutaka Tamura, Hidenori Mochizuki, Hajimu Kurumatani, Kiyoshi Okano, Mitsuko Miyamoto, A prostacyclin analog prevents the regression of renal microvascular network by inhibiting mitochondria-dependent apoptosis in the kidney of rat progressive glomerulonephritis, 16-26., Copyright (2014 Aug), with permission from Elsevier.

Changes in renal function

  • Decrease in GFR
  • Decreased urinary concentrating ability.
  • Decreased ability to adjust electrolytes.
  • Decreased hormone secretion capacity, etc.

By the time clinical signs such as loss of appetite, weight loss, decreased energy, polydipsia are seen, it is said that around only 30% of the kidney is still functioning.

Test items

Blood tests
・Serum creatine, blood urea-nitrogen (BUN)
Urinalysis
・Urine protein/creatinine ratio (UPC), urine specific gravity
Other tests
・Blood pressure, ultrasonic exam

and others…

Diagnosis will be made based on these test results, medical history and physical examination.

References

  1. 1)Sparkes AH, et al. J Feline Med Surg 2016; 18: 219-239.
  2. 2)Chakrabarti S, et al. Vet Pathol 2013; 50: 147-55
  3. 3)Yabuki A, et al. Res Vet Sci 2010; 88: 294-299
  4. 4)Nangaku M. J Am Soc Nephrol 2005; 17: 17-25.
  5. 5)Fine LG and Norman JT. Kidney Int 2008; 74: 867-872.