Posted by on Apr 22, 2015 in Tracking/Evasion | 2 comments

Most of us think of dogs as our companions, friends that will love us unconditionally so long as we feed them, exercise them and love them. But for some people, a dog can be an enemy. One that can attack and even kill, one that can discover hidden or illegal substances or one that can smell human scent. In this article I will look at dog that uses its nose’s to scent humans and to track them down, the most common and best known of the human tracking dog breeds, the Bloodhound.

Bloodhounds are the ultimate scenting dogs and there are packs which are used for tracking all over the world. Their origins date back to the Middle Ages Europe where they were originally used for hunting deer and wild boar. It is impossible for us to really comprehend just how good these dogs are at scenting and tracking humans. They can detect human scent days after a human has passed, they can scent over water and they can do this over long distances, and here is the thing, they are tenacious and perfectly designed for scenting and ‘trailing’ their target. They are so impressive at doing this that in some places in the world their results can be presented in court and are admissible as evidence.

Scent Dog

Everything about the dog is designed for scenting, including its face, ears shortish legs and long strong neck, but what makes a Bloodhound so exceptional is its nose or rather the olfactory (scenting) area inside the nose. In humans this is about the size of a postage stamp, in Bloodhounds it’s the size of a handkerchief! Physiologically the number of scenting cells inside the Bloodhounds nose is about 300 million, compared to a humans which is about 5 million, which in real terms means that this breed of dog, under optimal conditions, only needs to detect one or two human cells to lock on! Even more impressive is that these dogs can scent discriminate and lock onto the target scent once it is known by the dog.

Humans shed about 40,000 skin cells per minute approximately. The longer a person stands in one place, the stronger the scent becomes. It is this skin shedding that is the principle method of tracking that the Bloodhound uses. The record for picking up and tracking a scent is a dog that found a family dead 330 hours after going missing in Oregon, that’s nearly 14 days later!

Most of our knowledge or preconceptions about tracking/trailing dogs comes from Hollywood, such films as Cool Hand Luke, The Shawshank Redemption and others that feature these dogs sometimes give the impression that these dogs are easy to fool. In reality they are not. In experiments, trained and experienced dogs successfully tracked human subjects successfully 96% of the time. From our armchairs it is easy to think that we can distract these dogs. We may think that we can use peppers or other chemicals to disrupt their noses, we can’t, and a dog will simply work through them. We may think that we can use water to mess disrupt our scent, we can’t, this barely slows the dogs down.

Dog Tracking

Now I have been hunted by dogs before during a number of Escape and Evasion exercises, both in the UK and in Germany, but they were other breeds, mainly German Shepherd dogs, which are not dedicated scenting dogs and easier to evade than Bloodhounds. Going up against these dogs is not only an incredible challenge, but if you’re to be successful it requires a sound strategy and a certain degree of luck. I can reveal some of the considerations that I took into account and some general guidance.

I should state at this point that the Police Bloodhound Unit I was up against do not come up against soldiers with training in escape and evasion. I’m not a criminal running for my life, I’m a professional ex-soldier who’s served with elite units in the UK and had some excellent training in Survival, Escape, Resistance/Recovery, and Evasion/Extrication. Some of the emotions and tensions that a person on the run exude are easily detectible by scenting dogs. I, on the other hand, was cool and calculating. Not being intimidated by the dogs and having pre-formed strategies that could be implemented depending on the environment and the opportunity was key.


So, here are a number of things to take into consideration and some general pointers:

  1. Bloodhounds are single minded once they pick up your scent and can pick up the scent many days afterward.
  2. They can scent through shallow water through which you can wade, but have difficulty in water in which you can swim in.
  3. All a Police Bloodhound Unit need is an accurate location of where you were. They do not, as is commonly believed, require an article of clothing or object to obtain your scent.
  4. They are not disrupted by pepper, pepper sprays, CS gas or other chemicals and frankly if you are on the run you are unlikely to have access to these anyways. Do not waste time. Time and distance is your friend when evading dogs.
  5. Trailing teams do not need to rest at night. They can bring in relief teams to work through the night and operate shift patterns as the dogs are usually part of a pack. This means that you cannot afford to rest. Unlike the tracking teams you will not be able to use light to guide you through rough terrain.
  6. These dogs have incredible endurance and some have even died from exhaustion while scenting.
  7. If you cannot evade the dog, then target the handler. I am not suggesting taking the handler out, as mostly the dog is usually only one part of a professional tracking team and unless you are experienced in laying and initiating an ambush it is likely that this will get you shot or at the very least re-captured. A good team will have an experienced handler who can interpret the dog and also have a flanking armed security team for protection.
  8. Target the handler by exhaustion. Use the terrain and the vegetation to slow down the dog and handler. When these teams move through open ground trailing, they are very fast and the handlers are usually pretty fit.
  9. The dogs usually work in isolation with relief dog and tracking teams being brought in as required.
  10. Contrary to popular belief they usually do not bark when trailing, however the handlers will often be heard encouraging the dog. When this happens you need to do something quickly as they will be on you quickly if you continue without taking evasive or deceptive actions.
  11. Using places where lots of humans have congregated will likely slow down the dog, but with a good dog, it will only be a minor delay. Your scent is unique and the dog can discern your scent from that of others. However if you are being tracked by a younger or less experienced dog you have about a 50/50 chance of evading successfully.
  12. When moving over ground, use terrain that has little or no bacteria within it. Sand, concrete, and rocks all make it more difficult for the dog, but remember it will work through this eventually.
  13. Use deep water to swim through. Yes the handlers will know where you have entered, but now they have to figure out where you went and they will have to scan two sides of a watercourse, which all takes up time. The more difficult you can make this the better.
  14. Make the handler doubt the dog. This works best with an inexperienced dog or handler or both. Where time is on your side, put in multiple deceptions.
  15. Bloodhounds have been known to scent their quarry even when in a vehicle. Of course though this can be used to gain distance and time to be used to your advantage later.

Be under no illusions, these dogs are hard to evade and frankly Bloodhound Units are very well trained as are the dogs. A certain amount of luck goes a long way. There are some techniques that have not been discussed and will remain in the domain of the elite units, but generally speaking if you consider the measures above you will give yourself the best chance of being successful.

-Dave Connell


About the Author

Dave C is a 22-year veteran of the UK Armed Forces where he specialised in Combat Medicine. During his career he served operational tours in Northern Ireland, Cyprus, Desert Storm, Bosnia Herzegovina and served with the elite Medical Support Unit attached to 22 Special Air Service, UK Special Forces Group. He is also trained as a Combat Survival Instructor and has had a life-long interest in living and working in the outdoors. Since retiring he has remained active in the medical and survival industry, operating and teaching remote and operational medicine, risk management and survival in Afghanistan, Iraq, Turkey, Democratic Republic of Congo, Sudan, Syria, Lebanon and combatting piracy in the Gulf of Oman. He’s the founder of Survival Edge, created as a platform for training various hostile area safety courses including tactical pistol & carbine, tactical combat casualty care, situational awareness, urban/rural combat survival and bushcraft. Recently, he has been a Survival Consultant to numerous reality TV productions. He lives in Hereford, United Kingdom.