Future Farmers of America (FFA) Vet Science Career Development Events (CDE) Practice Exam

An increased heart rate is a common sign of stress in animals because when an animal experiences stress, its body triggers the "fight or flight" response. This physiological reaction leads to the release of stress hormones such as adrenaline, which prepares the body for a rapid response to perceived threats. As a result, the heart rate elevates to pump more blood and oxygen to vital organs and muscles, enabling the animal to react swiftly.

In contrast, decreased body temperature, stable respiration rate, and normal blood pressure do not typically indicate stress. Instead, they suggest that the animal may be in a calmer state, as stress is more likely to raise both heart rate and blood pressure while potentially affecting temperature and respiration as well. Therefore, observing an increased heart rate is a clear indicator of stress-related changes in an animal's vital statistics.