Monday, April 12, 2010

My pick for Book of the Month for April is "Scent and the Scenting Dog" by William G. Syrotuck. The first section of this book carefully describes a dog’s sense of smell. How just like with humans, while a smell can initially be strong, it grows less so the longer you’re around it. Syrotuck also describes how a variety of smells can potentially interact. While smelling one chemical before another, the two may be easily distinguishable only based on which is smelled first. There are also other smells that can so saturate the nose that it makes it very difficult for the dog to sniff out other smells for a period of several minutes after being exposed to this odor. There are also various body secretions that are able to influence a dog’s behavior. Secretions such as those from a bitch in season, urine, and chemical secretions given off by the emotion of fear.

The next portion of the book is spent describing the anatomy and physiology of the nose. What I found most amazing was the vomeronasal organ of the nose. This organ has 608 nerve bundles that have a direct connection to the olfactory lobe of the brain. 608 nerve bundles!!! That definitely helps to explain why dogs have such a keen sense of smell. Illustrations are included that not only help to visually explain the anatomy, but also to show comparisons between these areas in the dog versus the same areas in the human. It becomes very readily apparent why dogs have such a keener sense of smell in comparison to humans when 1/8th of a dog’s brain is devoted to smell versus an even smaller portion of the human brain.

Another point that I found very interesting from a working dog aspect is the importance that pigment of the whole nasal area plays. This is one of those things that tends to go into breed standards because the people writing the standard understand it, but those reading the standard who don’t necessarily have the working knowledge behind it, don’t necessarily understand the reasoning. The color of a dog’s nose may seem quite insubstantial when you’re reading the breed standard, however, pigment of the nose is very closely related to the dog’s ability to smell. Albinism in dogs and humans is directly linked to a defective ability to smell. This is QUITE important in a working dog! If they don’t have the correctly pigmented nose, this will greatly impact their ability to do the job that they were bred for. So the next time you’re reading a breed standard and you think it superfluous that they include the color of the dogs nose, now you will know that it is in fact quite important to the dog’s breed that it be correct. Without it, they couldn’t do the job they were specifically bred to do!

I would also like to bring up that throughout the book the author is citing actual scientific research that has been conducted on dogs and humans. The information contained in this book is not anecdotal, it is based on actual studies. While the studies are cited, the author will also explain potential pitfalls of the studies and where they may be lacking.

The next section is a description of the human body as a scent source. There is so much that goes into an individual’s smell, that each individual has a very unique smell. Things such as what you inherit from relatives, what environment you live in, what you eat, what your gender is, and what your ethnicity is all play a role in your individual scent. Syrotuck goes fairly in depth into the intricacies of our primary scent producing “organ,” our skin. While I’m not entirely sure why it’s necessary to know how all of this comes together on a cellular level with regards to scent work with dogs, it is mildly interesting. However, it seems like a section that could easily be skipped since he doesn’t directly talk about why this is important in tracking.

Next up is a description of how the human scent is transmitted. Around each living being is a body air current. For whatever reason, the air tends to all flow in the same direction regardless of what the person is wearing. It starts at the feet and continues to flow up the body, to the head, where it goes a bit higher and then dissipates around the body. After describing the body air current, the author then goes into a lengthy description of bacteria on skin rafts and how the bacteria change over time. Again, I’m not entirely sure how descriptions of bacteria and what they break down has direct bearing on the tracking dog. While I understand that it alters scent, it’s not like the dog’s nose has a running commentary on the state of the bacteria on the minuscule skin rafts.

After much talk about bacteria we go on to the ground scent picture. While the author does talk more about bacteria specifically in the soil and how it varies depending on the vegetation and interacts with the crushed vegetation, I think it’s easier to read around that part to get at the meat of the discussion. Basically there are two aspects to the ground scent. The first is the foot step with the impression that it makes and the various odors that it stirs up by the pressure of it’s passing. And secondly there’s the skin rafts that filter to the ground leaving the human part of the scent behind. The vegetation and climate will affect the metabolism of the bacteria on the skin rafts and influence the strength and duration of the individual scent that they exude.

Next is a discussion of the variations found on terrain. While two cross sections of ground may be relatively close to each other, the composition of these sections can greatly alter how well the scent “sticks” to the area. The soil type, vegetation, proximity to shade, and relative humidity all play a role. Since the scent is essentially a result of the bacteria on the skin rafts, you have to take into consideration how these different aspects of the terrain affect the rate of decomposition of the bacteria and thus the scent.

Once the general idea of scent and what can alter it has been discussed, the author goes into the details of the different “types” of scenting dogs. Those who are trailing scenters, tracking dogs, or air scenters. There is a difference in how these dogs go about following a scent trail. Within these divisions, dogs are also trained to focus on particular scents. Things like bomb detection dogs, drug detection dogs, or dogs who are used to find specific humans. Once you know which specific area your dog excels at then you figure out how to train and apply these skills.

Overall, I thought it was an interesting book and they it gives a good general overview to scent work with dogs. After having started reading a separate book that this author was a part of writing, I further understand why this book was written the way that it was. The author was a very influential person in early canine search and rescue training development. Both he and his wife also come from science based backgrounds, which totally explains why there was so much focus on the bacteria on the skin rafts and all the explanations about what goes on at a cellular level with human skin. It also totally explains the slant of this book with regards to search and rescue work. I had bought this book with the original intent of learning more about how tracking dogs work a scent. There have been other topics that I've briefly read about with regards to tracking dogs that are not discussed in this book. Since search and rescue dogs do a lot of air scenting, it stands to reason that that would be the focus of this book.

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