Document Type

Honors Project


Adviser: Dr. Julia Manor


Dog aggression affects many, with nearly 5 million dog bites reported yearly in the United States alone. With the physical, emotional, and monetary costs of bites, it is of considerable interest to identify dogs that are likely to bite. One physiological measure that might serve as an index of aggression is heart rate variability (HRV), which refers to vagally mediated beat-to-beat change in heart rate. Low HRV has been associated with impaired emotional and behavioral regulation and stress in both humans and animals. To assess whether this measure corresponds with aggression in dogs, resting HRV was measured for dogs with and without bite histories. It was observed that dogs with bite histories had significantly lower HRV, and that owner reported aggression negatively correlated with variability. HRV measurements were collected from multiple training classes in order to determine if HRV would increase with behavioral improvement and whether physiological changes would differ between non-aggressive and aggressive dogs. HRV measurements were recorded three times over six weeks of training. Low HRV was observed across most subjects, indicating that training classes were stressful for most dogs. However, some differences emerged between the classes. The lowest variability was observed in a class composed of reactive dogs enrolled in training for the first time (compared to other reactive dogs that had undergone more training). Implications of these results are discussed, as well as potential applications for treating aggressive behavior.



© Copyright is owned by author of this document