This isn't asking for vet advice. Info is for context. My whippet has a strange resting heartbeat. It's a couple of slow beats, then a few fast when she inhales. My vet has never mentioned her having a weird heartbeat, even when she was put under for a dental. A bit of googling indicates that it's common for sighthounds to have that sort if arrhythmia. Why would a whole group of breeds have that specific type of abnormal resting heart rhythm? What physiologically would cause such a thing?
It sounds like a normal sinus arrhythmia, where the heart rate speeds up or slows down depending on whether the dog is breathing in or breathing out. This is perfectly fine so long as the dog continues to breathe, and is present in a lot of fit dogs, not just sighthounds. It just happens that a lot of sight hounds are fit.
I usually take its presence as being a good sign, and this arrhythmia will disappear if you run the dog to make its heart rate go up.
- Dr Ferox
