2024-01-24 01:05:39
Where do heart problems in horses come from?
Cardiac arrhythmias, so-called arrhythmias, are not that rare in horses, says Dr. Feichtenschlager. Normally, the sinoatrial node, an area of heart muscle cells in the right atrium, sets the pace for the regular heartbeat. However, as a result of myocarditis, triggered by infections such as strangles or influenza, the remaining heart muscle cells often go crazy and give off additional impulses, so-called extrasystoles.
If these occur in large numbers, they lead to atrial fibrillation, for example: the atrium receives too many impulses at once, no longer contracts completely and no longer performs pumping movements. If left untreated, atrial fibrillation can lead to cardiovascular failure. Parasites such as worm larvae can also migrate to the heart muscle and cause damage there.
What remains is scars that influence the electrical impulses and disrupt the heart rhythm. Chronic respiratory diseases also increase the risk of heart problems: the right heart muscle has to work harder with diseased lungs because the resistance to blood flow in the lungs is increased. This causes him to tire quickly.
Heart problems in older horses
Aortic valve insufficiency often occurs in older horses, which means that this heart valve does not close properly. A genetic defect can also mean that the heart valves are too short and do not seal optimally. In a healthy heart, blood flow is transferred via the atrium to the ventricle with each pulse beat. However, if the blood flows back in the wrong direction through a leaky valve, the volume in the atrium may increase so much that the heart muscle becomes fatigued and atrial fibrillation occurs.
Pathogens can damage the heart
Pathogens can also damage the heart valves. For example, if a horse continues to exercise during an influenza infection, the viruses quickly travel to the heart and attack the valves. Inflammation occurs, which leaves scars and deforms the valves. But even seemingly healthy horses are at risk of heart valve injuries if the valves have already been damaged. If the heart suddenly pumps a lot of blood, for example if the horse is overexerted in an untrained state, the heart valves on the supporting apparatus may tear off.
When the aorta ruptures
A particularly sensitive area of the heart is the aorta, the main artery through which the body is supplied with oxygen-rich blood. “If the aortic wall is previously damaged, it can tear if the blood pressure rises under high stress or the horse is in a strong stretching movement such as jumping,” says Dr. Feichtenschlager. If the aorta ruptures, all the blood flows into the chest cavity, the horse collapses and dies. Fortunately, this injury is rare.
Symptoms of heart problems
“Many horses compensate for heart problems very well and are even able to compete in sports,” says the veterinarian. Heart defects or diseases are often only discovered by chance. Veterinarians should therefore regularly check breathing and heartbeat, for example when vaccinating. However, owners should sound the alarm when these symptoms occur:
- Loss of performance and refusal to perform
- Heavy sweating/post-sweating and slow recovery after exertion
Little wheel
Loss of performance, heavy sweating and slow recovery can indicate heart problems.
- Heart beats significantly too fast (more than 60 times per minute at rest) or too slow (less than 30 times per minute)
- rapid breathing (faster than 8 to 12 breaths/minute at rest)
- Nosebleeds
- Staggering, colic, swelling of the legs and lower abdomen, and collapse can indicate serious heart disease.
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When the heart causes problems
- Things to know about heart problems
- causes
- Symptoms
- Diagnose
- Treatment
- Proper prevention
- With expert knowledge from Dr. Alexandra Feichtenschlager, equine veterinarian and heart disease specialist
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