Atrial Fibrillation in Dogs: Heart Rhythm Management
Atrial fibrillation is a common arrhythmia in large dogs, often associated with dilated cardiomyopathy, requiring rate control to maintain cardiac function and welfare.
Key Facts
- Atrial fibrillation causes irregular, rapid heart rate that reduces cardiac efficiency
- Common in large breeds with DCM, and can occur as a primary arrhythmia in giant breeds
- Signs include exercise intolerance, weakness, syncope, and signs of congestive heart failure
- Rate control with digoxin and/or diltiazem improves cardiac output and welfare
- Conversion to normal rhythm is rarely achievable in dogs with persistent AF
Welfare Considerations
Atrial fibrillation welfare management focuses on controlling ventricular rate to restore adequate cardiac output. Uncontrolled rapid ventricular response causes exercise intolerance, weakness, and the welfare burden of congestive heart failure from inadequate cardiac output. Rate control medications improve cardiac efficiency and welfare, though cannot restore normal rhythm in most cases. Regular monitoring of resting heart rate at home helps owners track rate control quality. Dogs with well-controlled AF and appropriate medical management for concurrent heart disease can maintain good quality of life for extended periods.
What You Can Do
- Work with a veterinary cardiologist for optimal rate control management
- Monitor resting heart rate at home and report significant changes
- Give all medications consistently — rate control requires continuous medication
- Modify exercise to comfortable levels based on your dog's tolerance
- Schedule regular echocardiographic monitoring to assess cardiac function