horses snort
© Juniors Bildarchiv GmbH
Sounds happy to me
Horses appear to snort more when they're happy. The finding could be used to assess the conditions in which horses are kept.

The distinctive noise has long been thought to serve hygienic functions, removing phlegm, flies and more from the nostril - although some studies had suggested that horses that are well looked-after seem to do it more.

Martine Hausberger at the University of Rennes, France, decided to investigate by recording the snorting patterns of 48 horses in Brittany, France, living under different conditions. Some of the horses led restricted lives, housed in individual stalls and feeding on low-fibre meals. Others lived more freely, housed in groups and able to feed on grass and hay at their leisure.

The team found that the frequency of snorting was much higher in horses living in better welfare conditions, such as feeding in pasture. They also assigned "chronic stress scores" to each horse based on their living conditions. The higher the stress, the less frequent the snorts.

"We think it can be a useful tool for horse owners and caretakers to identify situations that the horse enjoys," says Hausberger.

Frans de Waal at Emory University in Atlanta says that it's becoming increasingly important to find behaviours indicating well-being and stress in animals cared for by humans.

"Further tests (such as hormonal stress measures) may be needed, but this is a great beginning for an animal known as emotionally extraordinarily expressive," he says.

The team will now investigate whether horses snort more when they are giving riding lessons, which might indicate they enjoy aspects of working too.