ISES 2010: to objectively measure the welfare of horses

Two weeks ago I wrote about my presentation at ISES 2010 and I promised then to write about other research that was presented at the conference. One subject that was recurring in several presentations was the horse's welfare when being handled and ridden. What the scientists are studying is the possibility of objectively measuring the horse's welfare.

Welfare
Welfare can be seen as either the absence of negative experiences, or as the presence of positive experiences. Whichever way you look at it, how can the horse's welfare be measured?

Physiological parameters
It is common to measure the horse's heart rate and cortisol levels.
Heart rate – a lowered heart rate is usually seen as an indication of positive horse welfare since it is commonly associated with a calm and relaxed horse.
Cortisol levels – cortisol is a hormone that can be found in the horse's saliva. The levels increase with stress.

So far so good, but there is one problem. Studies have shown that exercise and stress have the same effect on physiological parameters: heart rate goes up as do cortisol levels. Thus it doesn't seem to be enough to measure these things. The scientists suggest we also look at the horse's behaviour.

Behaviuor
When looking at the horse's behaviuor, welfare is defined as the absence of conflict behaviour. An example of conflict behaviour may be that the horse puts his ears back, opens his mouth, shies, kicks out. On the other hand, it seems not enough to simply study and interpret the behaviour of the horse because some horses also seem to suffer from so-called learned helplessness. Learned helplessness means that the horse is in a situation that is unpleasant but shows no conflict behaviour.

In the case of animals, the following experiment illustrates what learned helplessness is: A fish swims in an aquarium. A translucent glass wall is placed between the fish and its food. The fish will swim into the wall repeatedly to reach the food, but eventually gives up and stops trying to reach the food. Later, even when the glass wall is removed, the fish will no longer try to reach the food since it "knows" that it can't.

One study suggests that the absence of conflict behaviour in horses riding in the rollkur, hyperflexion or LDP (low-deep-round) is the result of learned helplessness. Although other measurable parameters indicate that the horse does not have a good time (for instance reduced airflow due to blocked airways as well as increased heart rate), these horses show no conflict behaviours.

Eye temperature
Research has also used infrared thermography. What they have done is to measure the heat that is radiated from the horse's eyes using a heat sensitive camera. Exactly what a decrease or increase in the temperature of the eye means seems to be a bit difficult to determine. Different studies have so far come to conflicting conclusions.

Welfare - objective or subjective?
The scientist that gave the final presentation at the conference was Camie Heleski from Michigan State University (you'll find her abstract on page 48). She argues that science alone cannot define what should be considered to be the welfare of horses, because science is never free of values and thus is not objective. I agree with this wholeheartedly. Heliski writes that the values we have affect how we define welfare, both for ourselves and for horses. T. Grandin has said that if a particular approach is not deemed acceptable to the ordinary airplane passenger, in the end it doesn't matter what science has proven. The horse's welfare is not just subjectively assessed by you and me. Those who are not actively involved in horses and that are "looking in" from the outside also have an opinion about what animal welfare is. This is especially true today, when science cannot provide conclusive answers to what welfare is for the horse.

How do you asses your horse's welfare when you ride and handle it?