Taking your dog's vital signs is the best way to know if he is ill. Anyone can learn to take vial signs but, because of the range that is considered normal, it is important to take vital signs on a regular basis, while your dog is healthy. That way, if you suspect that your dog is sick, you know what numbers are normal for him. Even if the numbers fall within the normal range, if they are very different from what is normal for your pet, it shows that something may be wrong.
Determine heart rate. Place your hand on your pet's chest, between the third and fifth rib. You should be able to feel the heartbeat. You can also measure the heart rate by taking the pulse on the inner rear leg, near the groin. Count the beats for 15 seconds and multiply by four. Normal heart rate is 60 to 140 beats per minute. Larger breeds typically have lower heart rates.
Rest your hand gently on your dog's flank to count respiration. Again, count for 15 seconds and multiply by four. Normal respiration is 12 to 25 breaths per minute. The breathing should be effortless and quiet. Panting can interfere with an accurate count, so, if possible, measure respiration while your dog is not panting.
Measure your dog's temperature by using a digital thermometer in the ear canal or a rectal thermometer. If using a rectal thermometer, clean the thermometer with rubbing alcohol and a cotton ball. Lubricate the tip of the thermometer with petroleum jelly and insert about one inch into the rectum. Leave a mercury thermometer in place for 2 minutes. If using digital, it will beep when it is ready. Normal temperature is 100 to 102.5 F. A low temperature may indicate shock or exposure, while a temperature over 106 can be life-threatening. Regardless of what type of thermometer you use, clean with rubbing alcohol and a cotton ball after each use.
Check your dog's mucous membranes. The easiest way to do this is by looking at his gums. They should be moist and pink. Dry gums can be a sign of dehydration. Pale gums can signal shock or low red blood cell levels. Dark red may indicate heatstroke or sepsis; blue, low levels of blood oxygen; and yellow gums can indicate liver problems.
Press your finger against the gums, then remove. Normal capillary refill time is 1 to 2 seconds. Very rapid refill may indicate sepsis or heatstroke, while slow refill times may indicate circulation problems.