Abnormal Heart Rhythm in Dogs

Abnormal heart rhythm in dogs, or arrhythmia, is more common in some breeds than others. Electrical impulses regulate the rhythm of the heart by controlling the contracting and relaxing of this organ. There are many factors that contribute to these electrical impulses, such as electrolytes in the blood, the nervous system, the overall heart health, and any drugs that are ingested.

Abnormal heart rhythm in dogs is known as arrhythmia. Arrhythmia is a condition that occurs when the electrical impulses that control the beat of the heart occur too slowly, too rapidly, or erratically.

When a dog has abnormal heart rhythm, he may show symptoms that will warrant a phone call and visit to the veterinarian. Symptoms of arrhythmia include:

• Rapid breathing
• Fainting
• Uninterested in exercise
• Weakness
• Lethargy

When a canine has a cardiac arrhythmia, the electrical impulses that control the heart muscle are abnormal.  In non-cardiac related arrhythmia, the heart rate is irregular because of habits or conditions that are not directly related to the heart. In cardiac-related arrhythmia, the heartbeat is irregular due to a direct correlation with heart health. Direct causes of this abnormal heart rhythm in dogs are:

• Congenital  heart defects
• Genetics
• The specific breed of the dog
• Environment
• Diet
• Infections of various types
• Diseases or illnesses that affect the heart rhythm
• Injury
• Ingesting any poisons

The symptoms of arrhythmia can develop over time or suddenly, such as fainting. Once you see the symptoms listed above, you will need to call the veterinarian. 

A stethoscope will be the main tool used to identify the arrhythmia, if it exists. The veterinarian knows exactly what to listen for in terms of heart rate, heart murmurs, and breathing. Once he listens to the heart, he may want to order an electrocardiogram, or EKG, to take a closer look at the way the muscles are contracting, if there are enlarged heart chambers, or if there is an abnormal signal in the heart. He may also do a complete battery of blood tests to see if there is an illness or disorder that may affect the rate of the heart. 

If the dog’s symptoms seem to be inconsistent, yet still evident, the veterinarian may have him wear a harness with a monitoring system to wear for a 24-hour period.

An EKG is an effective tool for showing where the problem lies. The pattern of muscular contraction in the heart is replicated on the EKG feed and can tell us which heart chambers are enlarged, and whether a signal generator within the heart is faulty.

Abnormal heart rhythm in dogs is treatable once the veterinarian can identify what causes this disorder. There are a few treatment options that may be quite successful in allowing your companion to live a long, healthy life. 

Identifying Underlying Diseases or Disorders

Arrhythmia that is related to or caused by an underlying disorder, once the disorder or disease is treated the irregular heartbeat should dissipate on its own. If your pet is having trouble breathing, he may need hospitalization for oxygen therapy and strict rest.

There are medications that can be given to regulate the heartbeat. Beta blockers can lesson or prevent the stimulation of the nervous system adrenergic (using epinephrine or norepinephrine) receptors responsible for any abnormally rapid cardiac action.

Digitalis

This is a medication used to treat congestive heart failure. Digitalis takes the pressure off the heart by relieving the fluid that gathers around the heart during congestive heart failure. It is also effective in correcting irregular heartbeat.

Pimobendan

Pimobendan is an effective drug in dealing with heart failure in dogs. If the irregular heartbeat is due to heart failure, this medication can help alleviate the arrhythmia. It may also be given in conjunction with other medications, if needed.

The veterinarian will give you specific instructions on what the dog can eat and cannot eat, and this depends on the type of arrhythmia he has been diagnosed with. He may put your loved one of a prescription diet for weight management since heavier dogs put more strain on their heart and circulatory system.  

Your dog may need to rest and stay calm, depending on the diagnosis. Many times, the dog can run, jump, and be as active as before, but if this is not the case with your loved one, your veterinarian will give you instructions on what to do.

If the arrhythmia was caused by a disease, then the veterinarian will let you know what you need to do to help control the disease, which in turn will control the arrhythmia. Arrhythmia alone can be managed for the rest of the dog’s life with consistent medication (if given) and changes in his daily diet and exercise routines.