You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Defibrillation is the last resort to restore normal cardiac rhythm to a heart that is in ventricular fibrillation

The use of electrical defibrillation is not widely applied in veterinary practice but it is a procedure which can be used successfully to resuscitate veterinary patients. Basically, two metallic paddles are applied on either side of the chest, or directly to the surface of the heart, and a short electrical charge is applied between them. Defibrillation with a DC current is recommended and the technique involves shocking the heart with increasing energy-level settings until the heart converts from ventricular fibrillation into normal rhythm.. 

Usually defibrillation is performed across the chest wall and the initial energy doses recommended are :

• For animals less than 7 kg body weight  -  use 2 watt-seconds / kg body weight
• For animals 8-40 kg body weight - use 5 watt-seconds/ kg body weight
• For animals over 40 kg body weight - use 5-10 watt-seconds / kg body weight

Rarely defibrillation is performed directly onto the heart, in which case a lower dose of 0.2-0.4 watt-seconds / kg body weight is recommended.

It is important to remember that successful defibrillation does not correct any of the underlying problems which resulted in the development of ventricular fibrillation in the first place, and that maintenance of adequate oxygenation, with positive pressure ventilation if necessary, is needed to avoid irreversible hypoxic damage to the central nervous system. In addition, other factors such as acid-base balance must be kept within the normal range if a successful recovery is to result. If high energy doses are used myocardial damage can be caused which produces abnormal ECG patterns.  

Updated January 2016