I noticed that my eight-month-old Bichon has an
irregular heartbeat. I don’t hear a
murmur, but she could have one. She is
scheduled to see her vet next month for her next
round of shots. Should I be concerned?

Rita
Kerens, TX

If your dog is healthy and active, probably nothing is wrong. Most irregular heart rhythms (also known as arrhythmias) in dogs, especially young dogs, are benign.

The most common type of arrhythmia in dogs is called sinus arrhythmia. The heart of a dog with a sinus arrhythmia will beat at different rates when she is in different stages of breathing. Although sinus arrhythmias aren’t exactly normal, they almost never cause any problems.

In addition to sinus arrhythmia, there are several other causes of irregular heart rates. Although these are rare, they can be serious. To be safe, you should definitely keep that appointment with your vet next month. She will be able to determine whether the arrhythmia is anything to worry about. A test known as ECG (electrocardiogram) may be necessary. As well, she can confirm the absence of a heart murmur. Most likely, your dog will turn out to be healthy.

However, while you are waiting for the appointment, please monitor your dog for fainting, coughing, lack of appetite, or decreased ability to run, play, or exercise. These are symptoms of more serious heart conditions, and if you see them you should see your vet immediately.