ACE and Cyanosis: However, 16 dogs in stage C had clinical signs (eg, cough (10/16), exercise intolerance (10/16), dyspnea (4/16), or tachypnea/labored respiration with pulmonary edema (2/16)) or cyanosis (1/16) and were treated with furosemide (8/16), angiotensin‐converting enzyme (ACE) inhibitors (2/16), spironolactone (1/16), or pimobendan (10/16).