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Severely Abnormal Heart Rhythm in Dogs


Ventricular Fibrillation in Dogs


Ventricular fibrillation (V-Fib) is a condition in which ventricle muscles in the heart begin to contract in a disorganized fashion, making them quiver. Due to this uncoordinated contraction, blood circulation may cease within minutes, which may be fatal. Although it can affect dogs at any age, it seems to affect those that are older.


Symptoms and Types


  • Systemic illnesses associated with cardiac disease
  • Previous history of heart beat rhythm problems (cardiac arrhythmia)
  • Collapse
  • Death




  • Absence of oxygen in inspired gases or in arterial blood or in the tissues
  • Blockage of the aorta (aortic stenosis)
  • Heart surgery
  • Drug reactions (e.g., anesthetics, especially fast-acting barbiturates, digoxin)
  • Electrical shock
  • Electrolyte imbalances
  • Hypothermia
  • Inflammation of the heart muscle (myocarditis)
  • Shock




Unless some underlying infection, metabolic problem, or other such condition is present, the results of routine laboratory tests are usually normal. Your veterinarian will, however, record the ECG (electrocardiogram) results, which is helpful in identifying V-Fib and other related heart problems.



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