As a result, dogs with this problem will be unable to maintain normal heart rates and many also suffer other changes in heart rhythm. (embracepetinsurance.com)
heart rate - > normal heart rate for a medium sized dog at rest is 80 - 120 beats per minute colour of the gums should be pink - > red, white or gray is abnormal capillary refill time - > is measured by pressing firmly on a pink part of the gums above the teeth and measuring how long it takes for the colour to return - normally the CRT of a dog is 1 - 2 seconds (always < 3 seconds) respiratory rate - > at rest the rate would be 10 - 30 breaths per minute (maec.ca)
More focus on Normal heart rate rhythm namely Apple Heart Study using data from apple watch and in association with Stanford Medicine. (techlustt.com)