Can Dogs Sense Injury?

It's no secret that dogs have an enhanced sense of smell, granting them the ability to sniff out and detect various items, from firearms to narcotics. It's less well known, however, that dogs also have the ability to detect injuries that even medical professionals did not know about. 

Have you ever noticed how your dog seems to already know you're getting ill before you do yourself? Alternatively, have you noticed that when you're sick, they become more attentive and sympathetic to your needs? It's not a coincidence that your dog reacts this way. 

Actually, it's their intelligence coupled with their superior smelling abilities that allow them to detect a wide range of scents, including those emitted by your very own injuries and/or diseases.

There are specific signs your dog will exhibit when they have detected an injury on you or others and knowing these signs can help you understand when your pooch is trying to send you this message, in case you haven't yet received it! 

The most obvious sign that your dog will show when they notice you have an injury is their change in temperament. Usually, this would entail your dog becoming more curious and attentive to you than normal (if you can believe it)!

You may also notice them mimicking your every move as you navigate your home, and once you finally do settle down, they will most likely nestle in right beside you. Being over-affectionate is one characteristic that is commonly seen in dogs when they're sensing injuries. They may show their affection by cuddling and placing their head into your lap.

Some reports have indicated that dogs will actually identify the injured area by physically pawing at it or pushing at it with their heads. All in all, your dog can and will definitely show signs of injury detection when they notice something is wrong, the trick is knowing how to read your dog.

It wasn't until the past few decades that our attention was brought to our dogs' unique ability to smell injuries. We have known for thousands of years that dog can undoubtingly help us when it comes to sniffing things out. 

During the mid-twentieth century, using dogs to assist in scent-detection grew in popularity when the United States created their very own Military Working Dog Program to begin training canines. The focus in the 1960's however, was not on finding injuries or diseases, but on detecting illegal narcotics and drugs.

In 1989, though, something very interesting caught the attention of doctors working at the King's College Hospital in London, England. According to the doctors, they had a female patient whose dog paid persistent attention to a mole on her leg, which turned out to be in the early stages of skin cancer. From here, the growing interest in canine cancer detection flourished. 

It was after the millennium that researchers began actively investigating if and how dogs can smell injuries and more specifically, what these injuries were. One study conducted in 2006 found that trained dogs could use breath samples of cancerous patients to detect both lung cancer (with 99% accuracy) and breast cancer (with 88% accuracy). 

Studies exploring dogs’ abilities to sense other disorders, such as narcolepsy and the onset of seizures, have also supported the notion that, indeed, our dogs are capable of detecting injuries. Even though research in this field is relatively new, it's constantly evolving, giving us a better understanding of our beloved pooch’s abilities.

Many of us have heard anecdotes about dogs knowing when something is wrong with their owners before they, themselves, know, but how much of this is actually rooted in scientific research? Well for starters, studies conducted throughout the past few decades have indicated that dogs have the ability to detect a variety of injuries, disorders, and diseases including migraines, narcolepsy, and even certain types of cancers. 

How exactly can they detect injuries and diseases, you might be asking yourself? Dogs have an olfactory system that is far superior to our own, due to biological differences in both their brain and inside of their noses. The region of the brain that is responsible for our ability to smell is proportionally larger in dogs (up to 40 times larger), compared to our own. The fact that the region of their brain dedicated to detecting scents is so large, indicates that their ability to do this is effortless, to say the least. 

Furthermore, the average dog has approximately 300 million olfactory receptors constantly on patrol inside their nose, whereas humans have only about 6 million. The job of these receptors is to communicate between the nose and brain. Once the receptors are activated by airborne molecules that land on them, they immediately deliver a message to first, the olfactory region of the brain, then to the other appropriate regions that allow the dog to interpret what the smell is.  

Inside of our pooches’ noses, you will also find what is known as the vomeronasal organ (also called Jacobson's organ). This organ is located in the bottom area of your pooch’s nasal cavity. Its function is to detect pheromones, which are chemicals unique to and produced by all species to communicate information about emotions and mating. This extra organ, coupled with the large olfactory area in their brain, gives dogs the advantageous ability to recognize scents that are both good and bad, that we ourselves cannot smell.

This brings us back to injuries and diseases. For simple injuries, your dog can most likely detect the smell of blood, which may right away draw their attention to your wound. With diseases such as cancer and epilepsy, studies have clearly shown us that dogs can indicate who has the ailments, just by smelling biological samples they provide. 

This supports the notion that dogs can sense certain disorders by noticing the unique and potentially unappealing odor that we emit when we have them. Scientists have not yet determined the exact chemicals our dogs are smelling when they detect disorders, but with further research, more light will be shed on our understanding of this phenomenon.

It is certainly possible to encourage and reinforce a dog's ability to sense an injury, using Operant Conditioning strategies and rewarding the behavior after it happens. Operant conditioning involves the use of consequences and rewards to strengthen or weaken a behavior. Using positive reinforcement when your dog has successfully identified an injury will surely reinforce their likelihood or trying to find another. 

Positive reinforcement entails giving your pooch a motivational stimulus after they have completed the desired behavior, that is, once they have found the injury. This motivational stimulus can be as simple as praising them orally (e.g., saying "Good Boy/Girl" in a positive tone), giving them physical attention (e.g., petting them), or rewarding them with a psychical treat (e.g., either a toy or food reward). As a result of the stimulus, the behavior is much more likely to occur in the future because your dog is associating it with the positive feelings they experience from being rewarded. 

Scent-training is what is used to teach dogs how to smell specific injuries and diseases by medical and science professionals, therefore encouraging the behavior to occur. Scent-training involves teaching your dog to recognize and react to certain scents by making the scents recognizable to them, and rewarding their behavior when they find it. 

An example of this could be if you cut yourself, you let your dog see and smell your wound following which, you immediately reward them for acknowledging it. Even though it won't happen overnight, countless pairings like this will teach your pooch to associate the smell of blood with a reward, making them even more likely then they already are to notice and respond to your injuries.