You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Sudden onset severe pulmonary oedema or sudden death in a dog known to have endocardiosis should raise the likelihood of the cause being ruptured chordae tendinae

The chordae tendinae are important structures that maintain the heart valve leaves in place, and prevent eversion or prolapse into the atrium despite the tremendous forces that are generated during the normal cardiac cycle. Chordae tendinae rupture has only been reported to occur in the mitral valve of dogs.

Clinical signs are those associated with acute pulmonary oedema, including :

• Severe dyspnoea
• Cyanosis
• Tachypnoea
• Dogs may panic if they are handled or forced to move
• Dogs may extend their neck and gasp to breath
• Clear or blood-tinged frothy fluid may appear down the nostrils or, occasionally, in the mouth
• When listened to with a stethoscope there are loud "bubbling" noises and crackles over the lung area.
• Rupture causes a sudden rise in atrial pressure and pulmonary venous pressure and acute left-sided heart failure

The diagnosis is confirmed by identifying a flail valve on echocardiography :

• Disorganised diastolic valve motion
• A mobile echo between the mitral leaflets during diastole
• Fluttering of the valve during systole
• Left atrial echoes during systole
• Prolapse of the mitral valve into the left atrium during systole

The prognosis for dogs with rupture of the chordae tendinae is poor.

Updated January 2016