Pain And Personality In Dogs

The quantification of pain in animals is necessary for numerous reasons, such as determining how to treat various injuries and ailments, and generally providing animal welfare. A pain judgement that is too high could result in giving too high a dose of anesthetics or painkillers, which could potentially have side effects and cause further pain or distress to an animal, On the other hand, a pain judgment that is too conservative could result in unnecessary suffering for the animal without the necessary relief. This makes it crucial that the scales we use to measure pain are valid and tested to reduce suffering for the animals. This issue is especially important in a veterinary environment, where a great deal of pain management and treatment takes place.

This study set out to determine whether dog personalities have an impact on their experience of pain. The researchers used a system called the “Monash Canine Personality Questionnaire- Revised” to determine the personality types of the dogs used; since they wanted to avoid any unnecessary suffering to the animals being studied, they only worked with dogs that were, regardless of the investigation, about to undergo a routine neutering in a clinical setting. The dogs were divided into two groups – extroverted and neurotic. The extraverted dogs were classified as typically active, excitable and restless. The neurotic dogs were classified as fearful, submissive and timid.

In the experiment, 17 dogs were observed from post-operation through the recovery period from their surgery. The researchers observed the core temperature of the dog during the start of the operation, 15 minutes post-op, and then 30 minutes after for several intervals. The researchers used a system called the “Short Form Glasgow Composite Measure Pain Scale,” which involves them observing the dogs’ actions such as their vocalization, attention to their wounds, mobility, and response to touch, among other criteria. They also measured emotional response to pain by measuring the dogs’ eye temperature using an infrared device, with any difference between the eyes being a sign of “lateralized cerebral blood flow,” which would reflect emotional pain.

What the study found was that there was no association with neurotic personalities and pain tolerance, or even showcasing of behavioral expressions. There was a correlation however, between extroverted dogs and higher peak pain scores. This supports the idea that extroverted dogs show behavioral expressions of pain more than other dogs. However, it’s important to note that behavioral indicators did not correlate with physiological responses. In other words, behavior might not be an accurate representation of poor welfare in an animal, and individual animals respond differently to the same procedure. The study also showed extroverted subjects having a possible greater increase in core temperature and increase in temperature in the right eye compared to the left. Further research would need to be done to understand these associations. Overall, the study found a peak in mean pain score across subjects of 3.13 out of a possible 15, which steadily declined over time. According to the researchers, this shows that, “on average, adequate pain relief was administered and pain was successfully managed during recovery.”

The researchers also asked human guardians to predict their companion dogs’ pain tolerance on a five-point scale. Interestingly, their predications did not correlate with their dogs behavioral and physiological responses to pain, which shows that a person’s knowledge of their companion dog is unreliable when predicting the dog’s response to pain. For companion animal advocates, the study shows that personality can play a key role in how dogs react to and express pain, and that veterinarians and human guardians need to work together to assess and manage dogs’ pain in a clinical and home setting.