Assessing Animal Emotions

UBC Reports | Vol. 53 | No. 1 | Jan. 4, 2007

By Assoc. Prof. Dan Weary
UBC Animal Welfare Program, Faculty of Land and Food Systems

Concerns about the welfare of animals are nothing new, but the best way to care for animals is not always clear. Now the developing field of animal welfare science is helping people make better decisions regarding animal care.

Cat owners, pig farmers, laboratory scientists and many others need knowledge-based recommendations on how to house and manage the animals under their care, as the requirements for good care are not always clear and some practices thought to help animals may also cause harm. For example, the cat owner may feel that his cat needs to explore, roam and hunt, but allowing the animal outside increases its risk of disease and injury. The pig farmer may wish to provide a nutritionally complete diet and prevent obesity in her sows, but feeding limited quantities of a concentrated diet can leave the animals in a chronic state of hunger. The laboratory scientist may wish to provide housing that prevents the spread of disease by using caging that is easy to wash, but the barren housing conditions that result can lead to mice spending much of their day engaged in stereotypical behaviours that are repetitive and non-functional.

UBC’s Animal Welfare Program provides research-based recommendations for animal care but faces three challenges in achieving this goal. First, good ideas that improve the lives of animals must also be practical. For example, horns on adult dairy cattle are dangerous for farm workers and injure herd mates, so the horn buds are typically removed from the calves using a hot iron. This is an unpleasant chore for the farmers, and painful for the calves. Research within the program has now developed a simple and inexpensive method of de-horning that includes sedating calves and preventing the pain, and this method also makes the chore of de-horning much easier to perform.

The second challenge is developing methods of assessing welfare. In the past scientists working in this area tried to define welfare in terms of their own biases or what they were able to measure. For example, animal scientists focusing on food animal production used measures of animal growth or productivity, and physiologists used measures of heart rate or blood cortisol.

Program researchers have led the field to the current consensus: conditions we provide animals should address concerns about animal health, the expression of natural behaviours, and animal emotions including pain, hunger and boredom.

This leads us to the greatest challenge in this field — how can we assess animal emotions? Assessing pain and other emotional states requires scientific innovations by program researchers.  Some simple approaches can provide great insights. Preference tests allow animals to choose between different environments, and have been used to assess what lying conditions cows prefer, and what housing conditions are important to rats. Animals can be provided treats in the less preferred environment to assess, for example, how much rats are willing tolerate noxious conditions. Measures of pain are validated using proven analgesics, and some work has shown that animals with painful injuries will select feed that has been dosed with analgesics. Now new work is suggesting that how animals think can be used to assess how they feel. For example, when dairy calves are provided a gambling task using a computerized milk feeder, calves ‘play’ less frequently when they become ill. This result indicates that clinically ill calves also feel ‘sick’, and could also lead to improved methods of early diagnoses and treatment on dairy farms.