In dogs and cats, pheromones have been used successfully to treat anxiety and phobias. Pheromones are substances secreted by the body, which have an effect on the behaviour of other animals of the same species. All lactating female mammals release substances called appeasing pheromones . Their function is to calm, and provide reassurance to the offspring, especially in unknown situations. They conribute to the foal bonding with the mare. Could pheromones have a place in calming anxious horses?
Research in France has looked at the value of a synthetic equine appeasing hormone (EAP)* in overcoming fear in horses. Dr Christelle Falewee and others, working at the Pherosynthese Research Centre, have been studying the effect of EAP on the horse’s response to a standard behavioural test.
Forty horses of various breeds, age and gender were used in the study. Some horses were calmer than others. Before starting the trial, an experienced trainer graded them into three categories of reactivity (fearfulness) - calm , showing signs of fear or likely to shy - according to their likely reaction when exposed to a potentially frightening situation.
The horses were divided in to two groups. The researchers tried to make sure they were similar in composition for sex, age and reactivity.
Each horse received two sprays per nostril 18 minutes before being led out of its stall for the test. One group of horses was treated with a synthetic equine appeasing pheromone (EAP) sprayed up the nostrils. The other group was treated with a spray that did not contain the pheromone, but was identical in all other respects. None of the people involved in the study knew which spray contained the EAP until the study was over.
Horses were tested by assessing their willingness to be led through a fringed curtain into a stable. This test is adapted from one of those used by the Haras Nationaux, the French breeding institution, to evaluate behaviour for selecting French breeding stock. None of the horses in this study had undergone the test previously.
The researchers monitored the horses’ heart rate during the test and recorded the time taken for the horses to walk through the curtain. They also made a note of whether the horse had to be encouraged with a long whip or if the curtain had to be partially removed.
They found that horses treated with EAP performed better. They stopped less frequently when they were faced with the fringed curtain and hesitated for a shorter time. These horses also had lower average heart rate and maximum heart rate, both during the test and throughout the trial.
It would appear that adult horses, as well as foals, are sensitive to EAP.
The researchers suggest that EAP could be useful to help with potentially stressful tasks. It could have applications in situations such as shoeing, transporting, a change of environment, or when introducing new types of work. As it takes about 20 minutes for it to take effect, the EAP would be most useful for predictable stressful events.
* Pherocalm® (France, Germany), Modipher EQ® (USA).
For more details see:
Effect of a synthetic equine maternal pheromone during a controlled fear-eliciting situation.
Christelle Falewee, Emmanuel Gaultier, Céline Lafont, Laurent Bougrat, Patrick Pageat.
Applied Animal Behaviour Science (2006) 101, 144 - 153.