Hicks horse

Mallorie Hicks leads her horse through a barn at her Tracy, Minn., farm. She shows horses and breeds rabbits for 4-H.

We have our horses auscultated (hearts listened to) for multiple reasons. During prepurchase examinations, we listen to the heart before and after exercise. When a horse is colicing, we listen to the heart rate so we know how painful they are. And before we sedate horses for dentals, we listen to their hearts to make sure they don’t have a murmur that could compromise recovery from sedation.

But what happens when during one of these auscultations, your veterinarian finds a heart murmur? Below is a case discussion on exactly that shared with owner permission.

Signalment: 21-year-old Warmblood gelding currently in work.

History: Always very well taken care of and healthy. Lately, he seems a little sore in his left front leg and went to an equine referral center for a lameness exam, radiographs and joint injections if warranted. During the flexions for the lameness exam, a heart murmur could be heard next to his chest wall. The referral veterinarian then auscultated the heart and noted a very pronounced murmur.

Discussion at our practice: How could this gelding have a heart murmur that was never heard before? The murmur could have become audible after his last dental. Maybe the murmur was there all along but he was never excited enough to make it audible.

We had a lot of questions. After the murmur was discovered at the referral practice, we listened to his heart before and after exercise and likewise noted the murmur post-exercise. At this time, we discussed with the owner that we could either continue to monitor him, or we could send him to a veterinary cardiologist.

The owner decided that he should go to the cardiologist so that we could know if his heart disease was so progressed that he would not be safe to ride anymore.

Cardiologist’s examination and report: A physical exam was conducted of which his vital signs were within normal limits. The murmur was graded a 4/6 and termed a left sided diastolic murmur.

Next, they conducted an echocardiogram, an ultrasound of the heart that is used to assess its structure and function. What this diagnostic tool found was a moderate aortic valve regurgitation with mild thickening of the aortic valve. Aortic valve regurgitation is due to degenerative valve disease that can occur in older horses and is the cause of the murmur. His left ventricle was also moderately increased in size which means that the heart is having to work harder to pump because the valve does not work properly.

The plan: The cardiologist deemed this gelding still rideable because he was not showing clinical signs of heart disease and because his aortic valve regurgitation and heart wall thickening were only moderate.

Strenuous exercise, however, should be avoided. If he would start having exercise intolerance, jugular pulses, distal limb edema (swelling), ventral (belly) edema, coughing, or an increased heart rate, riding should end and he should go back for another echocardiogram. His heart should be auscultated regularly and a recheck echocardiogram should be scheduled in six months.

Conclusion: This gelding is happily back at work. He loves his job and his owners were very happy to hear that he can continue to be ridden safely. We are hoping that his aortic valve insufficiency does not progress, but after our consultation with the cardiologist, we are prepared and have a detailed game plan in place.

The Vet Report is provided in conjunction with Prairie View Veterinary Clinic.