Dog and paw
© Derik Delong
The general outlook of a dog towards the world can influence that dog's risk of becoming anxious, stressed or suffering from other welfare issues. Dogs who are hopeful and optimistic are less vulnerable to emotional distress that those who are more pessimistic. Individuals of many species with a negative mindset are more likely to attend to negative stimuli, remember negative events and consider ambiguous stimuli more negative than individuals in a more positive emotional state. A negative outlook can therefore predispose dogs to suffer emotionally in conditions that may pose no threat to individuals with a rosier outlook.

People can more effectively prevent trouble if they know which dogs are most in need of assistance, but many ways of assessing a dog's view of life are extremely time consuming. Such techniques require extensive training and testing of dogs in various cognitive tasks, making their use impractical in most environments, including in shelters and rescue situations.

A new study provides evidence of a faster, easier method of assessing dogs that may provide insight into the risk to individual dogs of struggling with emotional issues related to stress. By simply evaluating each dogs' paw preference (being right-pawed, left pawed or the canine equivalent of ambidextrous), researchers can determine which dogs are more likely to be vulnerable to welfare issues.

There is very good reason to suspect that paw preference may relate to emotional resilience. An animal's tendency for a negative or positive reaction to the world is related to which hemisphere of the brain is more dominant. The emotional processing performed by each side of the brain is different. The left side of the brain inhibits fear, is more likely to encourage exploration of the world and the approach to new stimuli. The right side of the brain is more likely to promote withdrawal from new stimuli and to process fearful information. Since each side of the body is controlled by the opposite hemisphere of the brain, left-pawed dogs are more likely to be using the right side of the brain more often and right-pawed dogs are more inclined to use the left side more consistently. That means that left-pawed dogs are at greater risk of struggling emotionally in challenging situations.

A new study, "Cognitive bias and paw preference in the domestic dog, Canis familiaris", assessed dogs for paw preference and also measured their tendency for optimism or pessimism in a food-finding task. Dogs were given the standard Kong test for paw preference, which consists of watching dogs stabilize a Kong with their paws to get food out of it and counting how often each paw-left or right-is used for this purpose. In this way, they can determine whether a dog favors one paw over the other. The dogs were also trained to find food in a specific spot and then given food in another spot, either close by or far away. By measuring how quickly the dogs went to the new food site, the researchers could determine whether the dogs felt hopeful or discouraged about the likelihood of finding food there.

The results of the study indicate that dogs who favor their right paw have a tendency to be more optimistic than dogs who are ambidextrous or left-pawed. Dogs who were more strongly left-pawed were the slowest to approach the food bowl in its new location. The practical application of this research is a quick way to assess the likely emotional outlook of dogs in new and potentially stressful situations so that resources can be focused on the dogs who are most at risk of suffering in those circumstances. Though paw preference is not an exact predictor of vulnerability to emotional distress in any particular individual, this study reveals a general pattern linking these two factors.