Large red dog jacket with the words “Medical Detection Dogs” and "Medical Alert Dog" worn by dogs to identify minute odour changes emitted prior to a person’s medical emergency and alert them to take preventative action, and to identify COVID-19, 2020

In 2014, research by Medical Detection Dogs showed that trained dogs were able to detect tiny scent traces of different diseases equivalent to a teaspoon of sugar in two 50 metre sized swimming pools.

Medical alert assistance sees trained dogs matched with a partner who often get no warning about a potentially dangerous change to their health. These include Type 1 diabetes, Postural Orthostatic Tachycardia Syndrome (PoTS), Addison’s disease and severe allergies. The dogs are trained to detect minute changes in their partner’s scent and give a 5-10 minute warning when a medical emergency is about to happen. For people partnered with a Medical Alert Assistance dog, it reduces the chance of requiring an ambulance and a possible hospital stay and serious injury. Many clients and their families report an improved independence and quality of life.

The idea that dogs may be able to detect changes in people’s health via their scent, particularly for cancer, has been anecdotally published in medical journals since 1989. The first scientific study appeared in 2004 proving that dogs were more accurate than chance alone could explain. Medical Detection Dogs (MDD) is a charity founded by Dr Claire Guest in 2008. Alongside researchers, scientists, and NHS trusts, MDD has carried out numerous peer reviewed studies into the ability of trained dogs to pick up changes to human health and illness.