| Jeremy Wieland
How are dogs able to sense diseases like COVID and cancer?
Dogs have been trained to detect several human diseases such as cancer and, most recently, COVID-19.
Dogs are famous for their sense of smell. Genetics and physiology make them ideally suited for sniffing. They have several genes that code for olfactory ability and many more olfactory nerve cells than in humans. For centuries now, humans have benefited from this superb sense of smell to hunt, detect drugs and explosives and now sniff out diseases.
Dogs have smell receptors ten thousand times more exact than humans', which means the dog’s nose is potent enough to sense substances at concentrations of one part per trillion. Their sense is so subtle that they can notice the slightest change in human scent caused by diseases.
They help diagnose diseases like cancer
Dogs are eminently known for detecting cancer. They can be trained to smell several forms of cancer including skin cancer, breast cancer, and bladder cancer, using samples from known cancer patients and people without cancer.
In a 2006 research paper, five dogs were trained to identify cancer based on the birth samples. They could carry out this across all four stages of the disease. A study has recently revealed that dogs can utilize their highly evolved sense of smell to choose blood samples from people with cancer with almost 97 percent precision.
Dog against Covid-19
The latest example of dog identifying disease is Coronavirus SARS-CoV-2 that has caused the global COVID-19 Pandemic. According to a study published by the University of Pennsylvania’s Veterinary School, dogs can be taught to sense more than ninety percent of Covid-19 infections even when patients are asymptomatic. Authors of the study hope using dogs to sense Covid-19 in people could replace the need to quarantine travelers.
Using their extraordinary sense of smell -- which can pick up the scent of half a teaspoon of sugar in an Olympic-sized swimming pool -- dogs have already revealed that they can sniff out disorders such as cancer, malaria, and epilepsy.
Dogs may 'sniff out' asymptomatic cases
The scientists explain that the dogs' training would incorporate getting them to sniff odor samples from individuals with COVID-19 and teaching these dogs to distinguish the smells related to the disease from the smell of uninfected people.
They also note that dogs can recognize poor health because they are very good at sensing even small changes in skin temperature. Consequently, the dogs may be able to tell who has COVID without any symptoms instantly.
It is still uncertain which substances in urine generate the characteristic COVID-19 odor. Since SARS-CoV-2 not only attacks the lungs but also causes harm to blood vessels, kidneys, and other organs, it is assumed that the patients' urine odor also changes. Researchers have high expectations that respiratory diseases such as COVID-19 change our body odor, so there is a very high possibility that dogs will detect it. One more good reason for us to love our dogs.