Donkeys may provide a natural tick repellent

A new study reveals that donkey secretion could be resistant to a certain species of ticks.

The sebaceous glands of horses and donkeys emit an oily substance, called sebum, that keeps their skin moist. Researchers at the Federal University of Goiás, Brazil, along with colleagues in the United Kingdom, recently investigated whether this secretion could be resistant to certain species of ticks. They discovered that while horse sebum isn’t completely resistant to Amblyomma sculptum, a species of tick found in South America, donkey sebum does have a repellent effect.

After collecting the sebum from both donkey and horse participants, the researchers isolated the volatile compounds it contains. Five compounds were found in both species, while one – (E)-2-octenal – was only present in the donkey extracts. Further tests revealed that (E)-2-octenal was the only compound that showed promise as a potential tick repellent.

According to the study authors, (E)-2-octenal could be used to create a tick repellent for both humans and animals.