Abstract
In the present commentary, the clinical use and the associated side effects of angiotensin converting enzyme inhibitors (ACEIs), the cornerstone in the long-term treatment of chronic heart failure (CHF) in the small animal practice, were reviewed. Based on the present author's unpublished data, it was indicated that ACEIs might suppress the progression of CHF when they could be given to a dog with mild hear failure. Incresed blood urea nitrogen (BUN) during chronic angiotensin converting enzyme inhibition was also discussed.