As many veterinary professionals know, annually we see a great deal of envenomation cases by the European adder (Vipera berus) in dogs, and it is quite common in Europe. Among oedema and other clinical signs, these cases often include cardiac arrythmias, yet little research has been conducted in this area.

A recent paper published in the Journal of Veterinary Internal Medicine prospectively assessed cardiac changes (including both an ambulatory ECG and obtaining data on serum cardiac troponin concentrations) in 21 dogs within 48 hours of a confirmed adder bite.

The study found that over half of the dogs (57%) developed some form of cardiac arrythmia – all of which were ventricular in origin. Overall, 81% of dogs had increased serum troponin I (cTnI) concentrations at one or more time period. Of those that developed arrhythmias, it was noted that they had significantly higher concentrations of cTnI at 12 and 24 hours. In most cases the arrhythmias resolved without treatment and all the dogs survived.

In summary, arrhythmias in dogs bitten by an adder may be missed by an ECG and are more likely to be detected with ambulatory ECG. Monitoring of cTnI is recommended to identify dogs with cardiac injury from adder bite.