Cardiogenic Shock in Dogs: Causes, Symptoms & Treatment
Unfortunately, dogs, like us, can have severe heart problems. When the heart doesn’t work correctly, it cannot pump blood effectively. If that happens, a state of shock can occur. That state is called cardiogenic shock, and it is a life-threatening condition that should not be taken lightly. If your dog has heart issues, it is probably a good idea to learn more about cardiogenic shock in dogs.
Shock occurs when the dog's body has abnormally low or insufficient circulation to supply the body with proper blood flow. Heart failure is defined as a low output of the cardiovascular system despite the presence of sufficient blood. The body's tissue requires a certain amount of oxygen and other nutrients. This condition occurs when those needs are not met.
In dogs, there are four types of shock caused by heart failure. When experiencing any type of cardiogenic shock, the cells must convert glucose to lactate (the production of lactate acid) to be used as a short-term energy source when oxygen levels are low. The following are the different types of shock caused by heart failure in dogs:
Cardiogenic shock is the most common type of shock due to heart failure in dogs.
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Most causes of cardiogenic shock are associated with significantly reduced left or right ventricle function. Still, other conditions that can cause cardiac compression and lead to inadequate ventricle filling may also play a role.
Low cardiac outflow can result in dangerously low blood pressure, which reduces blood flow to tissues. Possible causes include leakage from the pericardium (the sac that surrounds the heart) or conditions that cause severe inflow or outflow obstruction to the ventricles. There are several causes of low cardiac output. The following are the causes of shock in dogs due to heart failure:
- Large-breed dogs with taurine (amino sulfonic acid) deficiency have dilated heart muscles
- Severe valve insufficiency or other end-stage heart valve disease
- Arrhythmia disturbances
- Pericardial constriction is a tightening of the sac surrounding the heart
- Sepsis (systemic infection) can cause a decrease in cardiac contractility.
- Phosphorus excess in the blood
- A clot in the lungs
- The presence of gas in the pleural (chest) cavity
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Even if you know nothing about cardiogenic shock, you will surely notice something’s going on with your dog. Most owners see their dogs start coughing, shaking and usually have prior heart conditions. The dog’s gums will become pale, and that’s when most owners decide to rush to the animal ER or call their vets.
As you might expect, such a severe condition will cause a slew of problems within the dog's body. That means the dog will experience a variety of symptoms. The following are the most common symptoms of cardiogenic shock in dogs:
- Mucous membranes that are pale (from decreased blood flow)
- Extremely cool extremities
- Heart rate and respiratory rate are both variable
- Crackles and harsh lung sounds
- The pulse is weak
- Muscle deterioration
- Mental drudgery
- A history of previously compensated heart disease and cardiac drug administration may be associated with cardiac decompensation.
- History of coughing, exercise intolerance, weakness, or loss of consciousness may raise the possibility of previously undiagnosed cardiac disease
Because there are so many potential causes for this condition, your veterinarian will almost certainly employ a differential diagnosis. This procedure is guided by a closer examination of the visible outward symptoms, ruling out each of the more common causes until the correct disorder is identified and treated appropriately.
Low blood pressure will be documented by blood pressure measurement, and electrocardiography may aid in the detection of arrhythmias. Pulse oximetry, a procedure that uses a device to measure oxygen saturation by fluctuations in light absorption in well-vascularized (blood-supplied) tissue during systole (contraction) and diastole (dilation), can detect low blood pressure. Blood gas analysis can reveal metabolic acidosis, a decrease in pH, and a decrease in bicarbonate concentration in body fluids, which can be caused by an accumulation of acids or abnormal losses of a fixed base from the body, such as in diarrhea or renal disease.
An x-ray of the chest may reveal an enlarged heart or evidence of pulmonary edema (congestive heart failure). Echocardiography can detect cardiomyopathy (heart muscle disease), heart valve disease, limited heart muscle contractability, or pericardial compression.
When dogs suffer from cardiogenic shock, they will most certainly be placed in intensive care at an animal hospital until their body stabilizes and they begin to respond positively to treatment. The underlying disorder that caused the cardiogenic shock will be treated more aggressively. Among the treatment options are:
Any fluid accumulated around the pericardium will be drained to help relieve pressure on the heart lining.
Fluid therapy will be administered by positive inotropes to strengthen the heartbeat once cardiac function improves.
Vasodilators are medications that help widen blood vessels in order to improve heart function and blood flow. To prevent muscle tightening and narrowing of the vessel walls, the cells within the vessel walls relax.
When blood flow is reduced due to cardiogenic shock, there is insufficient oxygen reaching the tissues. The dog who is recovering from the cardiogenic shock will need oxygen therapy. This can be administered through a mask, a cage, or a nasal tube.
An electrocardiogram will be performed to monitor the electrical currents in the heart muscle. This will also take pressure and blood pressure readings to ensure that any treatment for the underlying disorder is effective.
Your veterinarian will want to check your dog's heart rate, pulse intensity, mucous membrane color, respiratory rate, lung sounds, urine output, mental activity, and rectal temperature after the initial treatment.
The prognosis is determined by the dog's condition and age, the severity of the condition, and the underlying cause. Many dogs can live normal lives if the condition is monitored and the treatment for the underlying cause is effective.
It is critical to follow the veterinarian's aftercare instructions and keep all scheduled appointments for regular check-ups. During each visit, the doctor will examine the dog's heart and cardiovascular system and, if necessary, perform any routine tests to determine how well your companion is doing. Your dog will be happy and relaxed if you give them a lot of love and keep an eye on their symptoms.
World Dog Finder team