What does tachycardia indicate?

Tachycardia refers to an elevated heart rate, typically defined as a heart rate exceeding the normal range for a particular species. In veterinary practice, it's important to recognize signs of tachycardia as it can indicate underlying health issues, such as stress, pain, fever, or cardiac problems. Monitoring the heart rate is a critical component of assessing an animal's overall health, particularly in situations where the animal may be in distress or experiencing illness.

The other options provided do not relate to heart rate. Uneven pupil size can indicate neurological issues or pain but is not associated with tachycardia. Yellow discoloration of the skin, or jaundice, often signals liver problems or hemolysis, while references to gum tissue would pertain to oral health issues rather than cardiovascular status. Therefore, option A is the only correct choice relevant to tachycardia.