Common Heart Issues in Horses

the cause.
Many of the horses David sees have atrial fibrillation a type of arrhythmia. Atrial fibrillation also called Afib is an abnormal rhythm of the heart. In Afib the electrical signals that control heart rate and contraction become disorganized causing an erratic and rapid heartbeat. Horses can live for years with Afib but their performance may be affected.
There two main treatment options for atrial fibrillation oral quinidine administration which can have side effects like low blood pressure and gastrointestinal problems and transvenous electrical cardioversion TVEC where the horses heart is shocked back to a normal rhythm. TVEC is performed at veterinary hospitals with the capability to place catheters to the heart via cardiac ultrasound.
Congenital Defects
Congenital defects of the heart are those the horse is born with. These heart defects can be caused be a variety of issues such as the environment in which the horses dam was housed medications the mare was taking genetic defects poor maternal nutrition and other factors although it is often hard to pinpoint exactly why a defect occurs.
Similar to murmurs congenital defects can range in severity and potential health outcome horses may show no ill effects or have significant health issues related to the defect. Its important to remember that although congenital defects may occur they are rare.
Like with people one of the most common defects found in horses is a ventricular septal defect. This condition occurs when the wall that separates the two lower chambers of the heart called the ventricular septum does not close completely allowing blood to flow backward and causing the heart to work harder.
Other congenital defects seen in horses include patent ductus arteriosus a hole in the vessel that connects the pulmonary artery to the aorta and tetralogy of fallot a combination of defects that prevent enough oxygen from getting

into the bloodstream.
Ongoing Management of Heart Issues
Determining the initial cause behind a horses heart issue can be difficult and often the root issue is never determined. In addition to being born with the issues illness from toxins in some plants and cattle feeds can permanently damage heart muscle and exposure can be fatal says David.
Bacterial infection of a heart valve may lead to permanent scarring and a permanent heart murmur he explains. Some murmurs are considered to be the result of age and wear and tear but the majority of the time we cant determine what initially causes heart problems.
With regards
to cures David notes that unfortunately none exist at this time in equine medicine. However some treatments may improve heart function and may increase the horses longevity he says.
Additionally not all cardiac conditions require the horse to become a pasture pet.
Many horses may perform at a high level for a long period of time with several different types of heart murmurs David adds. Certain conduction disturbances arrhythmias make a horse dangerous to ride but there are a few arrhythmias where a horse may be ridden lightly safely for years. When exercise intolerance is moderate to severe due to a cardiac condition a horse should not be ridden.
Having a horse diagnosed with a heart issue may be intimidating but its important to remember youre not alone. Involving a veterinarian to tailor a management plan thats in the best interest of the horse is key as is keeping ongoing tabs of his heart health yourself.