Based on this small group of dogs, clinically important AV block does not appear to occur in the long-term for dogs with SND. Risks of lead perforation, complete dislodgment, and rising thresholds for pacing, possibly because of microdislodgment, may be related to the initial skill level of the operator or the leads that were used. Use of leads with reduced torque at the lead tip, higher flexibility, increased lead-tip surface of contact with the endocardium or, more likely, use of alternate locations for pacing in the small right atrium of dogs with SND may decrease the frequency of these complications.