Sunday, August 13, 2017

Ask A Guinea Pig: Guinea Pig's Average Heart Rate?

It's time for another installment of our Ask A Guinea Pig series, where we answer questions from our readers! Here's today's question: Kathy Newman asks: "What is a guinea pig's average heart rate?"

Answer: We actually found a fair bit of variation in the answers out there, but the general consensus seems to be that it's somewhere around 200 - 319 beats per minute. (For comparison, in humans, "A normal resting heart rate for adults ranges from 60 to 100 beats a minute," according to the Mayo Clinic. So guinea pig hearts beat quite a bit faster!)

According to the Merck Veterinary Manual, a guinea pig's resting rate rate is 200-300 bpm:

Doctors Foster and Smith's pet education website gives slightly different numbers: 240-310 bpm. Also, an article in Nature claims that: "guinea pigs have a heart rate of 200–250 beats per minute." In The Biology of the Guinea Pig (Joseph E. Wagner, ed.), they reported that in a 1971 study, "They recorded a mean rate of 275.5 beats per minute as a normal resting heart rate. A range of 229 to 319 beats per minute demonstrated wide individual variation. They also reported that the guinea pig, while often appearing quiescent, is keenly aware of environmental changes as reflected in heart fluctuations. Introduction of a rat into a guinea pig cage caused a distinct bradycardia (25% less than resting rate)" This reminded us of one of our previous Ask A Guinea Pig posts on dogs and guinea pigs, where we cited an anecdote about guinea pigs been much less scared after the dog passed away.

Interestingly, in The Biology of the Guinea Pig, they also note a 1972 study "reported that the heart rate was significantly (P < 0.001) slower in summer than winter." This might help partially explain the different numbers. They also provide the following table, summarizing past research on guinea pig heart rates:

And, if you were curious how you might actually go about measuring a guinea pig's heart rate, we found an article from 1998 describing their process:
"The investigated animals were familiar with a daily standard procedure which included weighing in a plastic basin since their first day of life. In order to avoid disturbing the animals we used this procedure as base for our heart rate measurement: The head of an electronic stethoscope (Bosch, Germany) was built in the weighing basin in a way, that it was directly under the chest of the Guinea pig (figs. 1 and 2). By using an underneath accessible adjusting device the stethoscope’s head could always be adjusted in an optimal position without touching the respective animal with the hands. The electronically amplified heart rate sounds and the animal’s identification were recorded with a commercial two-speed dictation machine (Sanyo, Japan)."

Keep those questions coming!

1 comment:

  1. Our vet says that our heart rate is too fast to count!

    ReplyDelete