Chronic Renal Failure

Introduction:

Chronic renal failure (CRF) is the most common renal disease in dogs and cats and incidence increases with age. CRF is characterized by irreversible renal structural damage that has progressed for months to years. The cause of CRF is usually difficult to determine. The diagnosis of CRF is based on the combination of compatible clinical signs, physical exams, and clinical pathology results.

 Pathophysiology:

The loss of nephrons and decreased glomerular filtration results in increased plasma concentrations of substances normally filtered by the kidneys. The accumulation of these substances leads to the uremic syndrome.

ulcers in the mouth of a uremic dogs The uremic syndrome is a toxic and severe form of chronic renal failure.

with the following clinical signs:

  • sodium and water imbalance
  • anemia ( decreased erythropoietin)
  • carbohydrate intolerance
  • neurologic and gastrointestinal disturbances
  • osteodystrophy
  • immunologic incompetence
  • metabolic acidosis
  • oral ulceration due to uremia,
  • hyperparathyroidism and gastritis.

 
Ulcers in the mouth of a uremic dog, Washington State University Vet Hospital Image database

http://imagedb.vetmed.wsu.edu/Default.htm

  



Potential causes of CRF:

amyloidosis neoplasia nephrotoxicants renal ischemia pyelonephritis
urinary outflow obstruction familial nephropathies renal calculi leptospirosis idiopathic
renal hypoplasia renal dysplasia SLE glomerulonephritis vasculitis ( with FIP)


Clinical signs:

Gross and Histopathologic Findings:

Atrophy, inflammation, fibrosis, mineralization of the diseased nephrons, hypertrophy and hyperplasia of the viable nephrons are the gross and microscopic changes of CRF.  End-stage kidney is the term used with generalized, progressive and irreversible and advanced renal diseases. The kidneys are shrunken, pale, tough, nodular and fibrotic.
 

Diagnosis:

Radiographs confirm the presence of small kidneys. Renal ultrasonography will show increased echogencity and loss of normal corticomedullary boundary. A renal biopsy is not routinely performed in animals with CRF unless the diagnosis is in question.
 

For more information:

Polzin, D.J., Osborne, C.A., Jacob, F., and Ross, S.  Chronic Renal Failure. Chapter 169. In: Textbook of Veterinary Internal Medicine: Diseases of the Dog and Cat, 5th edition. 2000.Ettinger and Feldman.

Nelson, R.W., Couto, C.G., et al. 1998. Chronic Renal Failure. In: Small Animal Internal Medicine. Mosby pp. 621-625.

 

Pubmed search:

canine chronic renal failure

feline chronic renal failure