In a pilot study at the University of Helsinki, dogs trained as assistants in medical diagnosis learned in just a few weeks to distinguish (by the smell of urine) patients with COVID-19 from healthy participants in the experiment.
“We were pleasantly surprised at how quickly the dogs learned to distinguish the new odor,” said Anna Heilm-Bjorkman, an associate professor at the Faculty of Veterinary Medicine at the University of Helsinki. Dogs identify the odor with an accuracy close to that of PCR tests, she added.
A discovery with a future
Promising results from Finland will also serve other teams that train search dogs to get involved in the fight against COVID-19. The German Assistant Dog Center says they need more information on whether training with the virus is safe for humans and animals. “Virologists have advised us not to do it – in the end we know too little about the virus so far,” said Luca Barrett of the organization.
It is not yet clear which substance in the urine helps animals recognize the presence of COVID-19. The virus affects not only the lungs but also the blood vessels, kidneys and other organs. Probably this is how the smell of patients’ urine changes, which helps dogs respond to the disease.
Dogs recognize malignant tumors
“According to one study, dogs are 93 percent more likely to recognize leukemia and 97 percent more likely to have lung cancer,” Barrett said. Animals can also identify other cancers, including skin, colon, ovarian and prostate cancers.
Dogs also recognize Parkinson’s disease – years before the first symptoms of the disease, which is extremely helpful in early diagnosis. Animals also train to identify malaria. At the moment, however, they know 7 out of 10 infected, which is not enough.
At times stronger sense of smell than human
The sense of smell in dogs is about one million times stronger than in humans. Humans have about five million olfactory cells, the dachshund 125 million, and the German Shepherd 220 million. Dogs take 300 short breaths per minute, thus the cells of the sense of smell are filled with new particles constantly. In addition, they perceive different odors on the left and right – so they can simultaneously feel their surroundings and pursue a specific trail.
The Labrador Retriever, Cocker Spaniel and Shepherd breeds are among those trained to detect drugs and explosives. However, each dog can be taught to detect only one type of cancer. Also in France, dogs are being trained to respond to the new coronavirus
Dogs are trained through containers that contain odor or sweat. Once they identify the smell, the dogs hear a “click” and receive a reward in the form of food.
Valuable helper in the fight against COVID-19
Currently, few animals and their owners work in hospitals, and on a voluntary basis. Classical medicine and health insurance funds are largely skeptical of this method of early diagnosis.
If the findings in Finland are confirmed, search dogs could be a valuable helper in the fight against the new coronavirus. According to Luca Barrett, they can help prevent the spread of the infection at football matches, major events or at airports. And not just to check passengers. Search dogs can crawl the planes before passengers board to determine if there is a COVID-19 on board.