Horse Side Vet Guide ®

Equine Health Resource

Kidney Failure, Acute Renal Failure

Acute kidney failure can occur when a kidney-toxic substance in the bloodstream causes direct damage to the kidney. In horses, it is more commonly a consequence of underlying intestinal disease (conditions causing colic) that cause dehydration and poor blood flow to the kidneys. This lack of blood flow itself can result in kidney damage. Tying-up (exertional rhabdomyolysis) is also a common precursor to acute kidney failure.

NSAIDs like bute and flunixin (Banamine) when given in excess, can cause renal failure in the horse. Young foals are even more at risk for these toxicities.

Horses in renal failure are depressed and lack appetite. They either urinate very frequently or hardly at all. Inability to excrete toxins cause them to build up in the bloodstream and make the horse feel ill. This is what causes depression and loss of appetite.

Veterinarians usually diagnose renal failure with routine blood work. BUN and creatinine are two commonly used indicators, as are other enzymes and electrolytes. Urinalysis is very helpful in assessment and management.

Buildup of waste products, called uremia, causes a whole host of problems in other body systems. Treatment is an attempt to reestablish kidney function. The mainstay of treatment is intravenous fluid therapy. In some cases, diuretics are used to stimulate urination.


  • Did an underlying disease contribute to this, or a specific toxin?
  • What effect does the buildup of toxins normally excreted by the kidney have on other body systems?

    Avoid excessive use of NSAIDs (bute and Banamine) and any other drugs that may be kidney-toxic without strict veterinary guidance and monitoring.

    Prompt veterinary diagnosis and treatment with laboratory work to ensure adequate hydration levels. Sometimes this can only be accomplished through referral to an equine hospital where large volumes of intravenous fluids can be delivered and monitored.

    Helpful Terms & Topics in HSVGWritten, Reviewed or Shared by Experts in Equine Health

    Author: Doug Thal DVM Dipl. ABVP


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