Spironolactone Drug Handout

What is Spironolactone?

Spironolactone is more than just a diuretic (water pill). It does cause water loss by the kidneys but also decreases scarring within the heart muscle itself.


  • Congestive heart failure in dogs and cats
  • Sometimes used in advanced heart disease before congestive heart failure
  • Dilated cardiomyopathy (weak heart muscle disease)

Possible Negative Effects

Please contact CVCA if your pet shows any of these signs

  • Loss of appetite, vomiting or diarrhea
  • Minty taste can cause drooling in cats
  • Abnormal blood values – Increased potassium level or kidney values
  • Itchy skin on the face is uncommon but can happen in cats

Client Information

  • Can be given with food and other cardiac medications
  • Given once a day in cats and twice a day in dogs
  • When pets are taking this medication, they need to have a blood test at least every 6 months
  • Contraindicated in patients with Addison’s disease or elevated potassium levels

Interactions with Other Drugs

Standard Dosage Forms

Synonyms: (Spironolactone, Aldactone)