The Impressive Covid-Sniffing Dogs

If you’ve heard about COVID-sniffing dogs, you’re probably curious to learn more. The dogs that are used for COVID detection have been trained and tested for over a year and have been passing the tests with flying colors.  

Read on to see how the whole process works and its impact on the COVID pandemic.

How Do Sniffing Dogs Work?

Sniffing dogs are a subtype of work dogs that help with various tasks. They’re mainly used for military and police work, for bomb and drug detection. Recent studies, however, find that they can be extremely useful for medical purposes too. But how do these dogs detect illnesses?

Diseases and Smell

When you are sick, your body releases an organic compound that evaporates and creates a specific smell. This smell allows dogs to distinguish between a sick person and a healthy one. They can even recognize and differentiate between different diseases.

This works because a dog’s nose is a real-time chemical detector. Dogs have one organ humans don’t have — Jacobson’s organ. Jacobson’s organ is located in their nose and allows for easier chemical signal detection. 

Also, their nose has 300 million receptors, while in comparison, a human nose has only 6 million. Their sense of smell is also 40 times stronger than ours. 

When it comes to their capacity to detect odors, they beat us by far. Dogs have 10,000–100,000 times more ability for detecting different odors than humans

Use on Illnesses

By smelling the sweat or urine samples, dogs have been successfully tested to detect many illnesses, such as diabetes, cancer, and Parkinson’s. 

A study has also found that by sniffing urine and breath, dogs have a 97.6% accuracy in recognizing those sick of cancer

COVID-19 and Dogs

In the beginning, antigen tests and PCR tests were the only ways of finding out if somebody was COVID positive. However, today, dogs could be a great addition to the diagnostic tests too.

Research and Trials

There have been many studies and trials on sniffing dogs to see if dogs can smell Covid-19. All have found that dogs can, in fact, do that — and they’re very effective in doing so. A study has also found they can distinguish it from other respiratory viruses

However, before dogs get used in real-life situations, more studies and training need to be performed. For now, these are the findings.

  1. The first studies were performed on saliva samples. For one of these studies, eight dogs were trained for one week. After one week of training, they could detect the difference between COVID-positive and -negative samples in 82.63% of cases

Later on, urine, sweat, and saliva were used. 

  1. One study by French and Lebanese scientists found that trained dogs could recognize COVID-19 by smelling sweat samples from people’s armpits. The dogs were successful in 76% to 100% of cases, depending on the individual dog. 

However, this study found that dogs are easily distracted and can make mistakes if they’re exposed to noise. This can present problems in real-world conditions.

  1. For one research on COVID-sniffing dogs in 2021, laboratory live tests were performed, where the dogs showed 95.2% accuracy. In addition, the dogs correctly predicted 99.5% of all negative cases. On the other hand, 69.7% of all positive cases dogs detected were really positive. 

Among false positives, there were cases where the people who tested false-positive developed symptoms of COVID-19 soon after the testing. This can suggest that dogs can sometimes recognize the disease before PCR and antigen tests can. 

This test was also performed in real-life conditions in a metro station. Then, 99.0% of all people marked as negative were really negative. The dogs were not as effective in predicting positive cases, though. Only 28.2% of those marked positive were, in fact, positive.

This can mean that although the dogs are great at sniffing COVID-19, they need to be trained more for real-life situations. 


To be able to detect COVID-19, the dogs must be trained. How is it done? 

The trainers introduce different boxes with sweat samples to dogs, some belonging to COVID-positive patients, some to COVID-negative, plus the added no-sample and an empty box.

They use positive reinforcement training to make the dogs wag their tail, sit down or lie down in front of the COVID-positive sample. Once they recognize the positive sample correctly, they are given a treat. 

What Type of Dogs Can Be Used for Training?

Only work dogs that are easily trained and highly obedient can be used. Most of them are already used by the police and are better known as K9 dogs. One of the most used dogs is the German Shepherd, which has 85–88% accuracy, higher than some antigen tests.

Other breeds commonly used are Dutch Shepherd, Belgian Malinois, and Labrador Retrievers, one of the most popular breeds

Uses of COVID Smelling Dogs

There are many ways of using these dogs. However, the most convenient use of COVID-sniffing dogs is in airports, where they can save some precious time and reduce the inconvenience for many people.

For example, let’s say that among the passengers of one plane, which can have more than 200 people on board, three passengers are COVID-positive.

They would either all have to be tested or quarantined. However, if a dog separates 35 people from that crowd (90% accuracy), only they would have to be tested. 

Also, since even antigen tests need at least 15 minutes to get results, dogs can help a lot. For example, two dogs can sniff an entire plane in only 30 minutes.

In the end, the cost will be much lower, as PCR tests (and quarantine) will be used only for a small number of people.

Other uses are in high-traffic places, such as bus and train stations, concerts, and sports games. The uses are multiple but need further checking. What’s important to note is that dogs are by no means a complete substitute for PCR tests but can be of great help. 

For now, only a few places have started to use dogs that can detect COVID-19. One of them is the Miami Airport, where the dogs check the employees. 


Can Dogs Smell COVID

Yes, they can. All the studies done to this date confirm that dogs can smell COVID-19. Some dogs even have a higher success rate than some antigen tests.

Can dogs smell vaccines for COVID 19?

There is no proof that dogs can smell vaccines. Scientists haven’t performed any research in this field to this date. What is known is that dogs can smell COVID-19, but we’re not yet sure if vaccines produce any smell.

Can you smell COVID in the air?

It’s impossible to smell COVID in the air. There are smells that the diseases create, but only super-smellers, dogs, and some cats can smell them. And even they need sweat, saliva, or close breath to be able to smell it. 

Can you train your dog to sniff COVID-19?

There’s a low to no possibility that you’ll be able to train your dog to detect COVID-19. To do this, you’ll have to be able to train them as a professional would. You would also have to have access to different samples. 

Plus, it can be dangerous for both the owner and the dog to try this out.

Are dogs able to detect COVID-19 by sniffing armpits?

In theory, yes, they can. A study has found that dogs can recognize COVID-19 in sweat. However, no studies have tested it directly on people’s armpits.

Final Thoughts

Dogs that can detect COVID are a great addition to the antigen and PCR tests and can be of use in lowering infections. 

With an accuracy of around 90%, it’s clear they’re working exceptionally well. But, more research is needed, and the dogs should be trained more for real-life experiences. 

What is certain is that COVID-sniffing dogs are here to stay and will find their many uses in no time.

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