Felis ISSN 2398-2950

Kidney: acute renal failure

Synonym(s): Acute kidney injury (AKI), acute tubular nephrosis

Contributor(s): Penney Barber, Nicki Reed, Melissa Wallace


  • Syndrome with abrupt deterioration in renal function.
  • Cause: toxins/drugs, infection, renal ischemia.
  • Signs: uremia, oliguria (in most cases), anuria or polyuria (less commonly), dehydration, lethargy.
  • Treatment: prompt treatment to limit renal damage.
  • Prognosis: guarded, depending on unerlying cause; mortality may be high and extensive renal damage may result in chronic renal failure.
    Follow the diagnostic tree for Acute Renal Failure Acute Renal Failure.



Acute tubular necrosis

Pre-renal ARF

Post-renal ARF

Predisposing factors


  • Pre-existing renal damage with additional insult, eg reduced renal perfusion.
  • Any cause of reduced renal blood flow.


  • Anesthesia, especially without appropriate blood pressure monitoring and IV fluid support.
  • Chemotherapy with cisplatin.
  • Access to antifreeze (ethylene glycol).
  • Misuse of NSAIDs, aminoglycosides, diuretics or vasodilators.


Four phases

  • Initiation phase (renal insult resulting in damage to renal parenchyma; injury potentially reversible at this stage; hours to 1-2 days).
  • Extension phase (ongoing cellular injury progressing to cell death, with progressive decline in GFR and loss of urine concentrating ability).
  • Maintenance phase (elimination of inciting factors at this stage does not alter existing damage or rate of recovery; signs of uremia may be present; a prolonged maintenance phase is associated with slower recovery and increased likelihood of permanently reduced renal function).
  • Recovery phase (progressive return of renal function).
  • Reduced renal blood flow   →   reduced oxygen and energy transport to cells   →   cell swelling and membrane damage   →   vasoconstriction and inflammatory mediator release   →   further vasoconstriction.
  • Nephrons are damaged at different sites (glomerulus, tubular cell, intercellular junction, basement membrane) depending on etiology   →   acute decline in glomerular filtration rate   →   increased urea/creatinine, decrease in urine specific gravity   →   uremic signs, oliguria (sometimes anuria or polyuria), fluid and electrolyte imbalances, acidosis.


  • Animals may die acutely, especially if underlying cause is not detected and treated or if oliguric phase persists.
  • If treated appropriately, animals may recover, but recovery phase can take >3 weeks of intensive care.


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Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Dorval P & Boysen S R (2009) Management of acute renal failure in cats using peritoneal dialysis: a retrospective study of six cases (2003-2007). J Feline Med Surg 11 (2), 107-115 PubMed.
  • Worwag S & Langston C E (2008) Acute intrinsic renal failure in cats: 32 cases (1997-2004). JAVMA 232 (5), 728-732 PubMed.
  • Sigrist N E (2007) Use of dopamine in acute renal failure. J Vet Emerg Crit Care 17 (2), 117-126 VetMedResource.
  • Stokes J E & Forrester S D (2004) New and unusual causes of acute renal failure in dogs and cats. Vet Clin North Am Small Anim Pract 34 (4), 909-922 PubMed.
  • Grauer G F (1998) Fluid therapy in acute and chronic renal failure. Vet Clin North Am Small Anim Pract 28 (3), 609-622 PubMed.
  • Grauer G F (1996) Prevention of acute renal failure. Vet Clin North Am Small Anim Pract 26 (6), 1447-1459 PubMed.
  • Ohashi F, Awaji T, Shimada T et al (1995) Plasma methylguanidine and creatinine concentrations in cats with experimentally induced acute renal failure. J Vet Med Sci 57 (5), 965-966 PubMed.
  • Mealey K L, Boothe D M (1994) Nephrotoxicosis associated with topical administration of gentamicin in a cat. JAVMA 204 (12) 1919-1921 PubMed.

Other sources of information

  • Langston C (2010) Acute Uraemia. In:T extbook of Veterinary Internal Medicine7th edn. Ettinger S J & Feldman E C (eds). W B Saunders, pp 1969-1985.
  • Chew D J & Gieg J A (2006) Fluid therapy during intrinsic renal failure. In: Fluid, Electrolyte and Acid-base Disorders in Small Animals. Di Bartola S P (ed). W B Saunders, pp 518-540.
  • Frenier S L & Dhein C R (1991) Diagnosis and management of acute renal failure. In: Consultations in feline internal medicine 1. (ed) J R August. W B Saunders. pp 281-288.