Smoothing out the Lumpy Bits; Why it might be wise to teach the indication before the search and all that back chaining stuff

At its most basic, Scent Detecting requires your dog to search for, and locate, the source of an odour. On this simple description, your dog is engaged in Scent Detecting activities (entirely independent of you) for a very large portion of his day; finding a dropped crumb of food on the floor, discovering where a passing rabbit has left some tasty deposits, examining your clothes when you return home at night.

A little bit of independent Scent Detecting.

As Horowitz et al (2014) point out, your dog’s Umwelt or “Self-World” is primarily olfactory; “Dog noses house hundreds of millions more olfactory cells than humans’ do, and their corresponding brain regions are much more developed relative to their visual areas than in humans“.

So, what differentiates your dog’s independent Scent Detecting activities from those that involve you, his handler?

One word … Training

Well, two actually … Careful training

Ok, three … Careful, thorough, training!


Careful, thorough, training

Given your dog’s natural Scent Detecting talents, it can be hugely tempting to simply let him ‘get on with it‘. Spend a few minutes browsing any social media platform and you’ll soon find plenty of examples of this laissez-faire approach to Scent Detecting training, often with highly questionable results.

Yes, olfaction is your dog’s speciality but he isn’t Lassie! He can’t read your mind, guess what you want or speak your language. If you want him to find a specific odour for you – truffles perhaps – then you need to find some way of harnessing his natural abilities … some way of communicating your particular scent detecting requirements to your dog that might just differ from his own! And this is where careful, thorough, training comes into play.


Splitting vs Lumping

I start by splitting my Scent Detecting training into three separate, but interconnected, phases;

  1. Familiarising my dog to the target odour.
  2. Training the passive indication.
  3. Searching.

By splitting I am referring to the process of dividing the whole training task – in this case, Scent Detecting – into smaller, more manageable, training elements as opposed to lumping all three elements together and training them as a whole (Berg, 2018. Zerubavel, 1996).

According to Zerubavel (1996), “although the world in which we live is essentially continuous, we experience it as discrete chunks: strangers and acquaintances, fiction and nonfiction … Carving out of reality such ‘islands of meaning’ involves two contrasting yet complementary cognitive acts – lumping and splitting. The former entails grouping ‘similar’ things together in a single mental cluster. The latter involves perceiving ‘different’ clusters as separate from one another“.

In short, splitting makes our world, and our training, more manageable.


Why Split the training?

Well … the simple answer is … I like my Scent Detecting training to progress as smoothly as possible. I don’t like lumps!

I don’t like lumps in my Scent Detecting training!

If, as seems common practice, I were to lump my scent detecting training together and set my dog off to search an area before he’d been familiarised to the target odour and had a trained and reliable indication, how would I manage the following possible outcomes?

  1. He seemed to search the area very well but he didn’t find the target scent source.
  2. He definitely found the target scent but he pulled it out of the box, ran around the room with it in his mouth and chewed it up.
  3. He didn’t move from my side.

How do I let my dog know which bits he did well and were exactly what I could have hoped for and which bits were (to my view) just plain wrong? How can I reward his thorough searching in outcome 1 even though he didn’t actually locate his target scent? How can I reward my dog for locating his target scent in outcome 2 when he then went on to chew it up? And what on earth do I do about outcome 3?

Tricky, isn’t it? …. and this is what lumpy “training” looks like. Messy. Confused. Frustrating. Directionless. Unreliable. If our dogs learn anything from this lumpy approach to training, it would seem to be despite us rather than because of us. In contrast, splitting allows us to work on one specific training element at a time, helping to ensure competence in that area before moving on to another training element and then, eventually, putting all the elements together in one Scent Detecting whole or Lump.


But Splitting the training is so time-consuming, isn’t it?

Well, NO … it isn’t.

Splitting your training into smaller elements allows you to simplify things for your dog, aids clear communication, reduces frustration and increases your chances of getting things right in the first place without the need to add in further, remedial (Sticking Plaster), training at some later point in time.

Splitting your training results in …

  1. easily understood and manageable steps toward a larger end-goal.
  2. tiny bits of behaviour that, when successfully achieved, will allow you to reward your dog immediately.
  3. tiny bits of behaviour that, when things don’t go so well, will allow you to identify and address the problem rapidly with a revised training plan and approach.
  4. no need for your dog to “guess” what is required of him → less frustration → increased likelihood of training success.
  5. no wasted opportunity to reward a well executed behaviour because it’s been lumped together with a whole host of other, poorly executed, behaviours.

When you Split … always keep the Lumps in mind!

Although I’m a big advocate of splitting, it’s worth keeping in mind that there will always be connections between the different phases of training and the overall end goal. In other words, never lose sight of the training lumps! For example, the process of familiarising your dog to the target odour (Hall et al, 2014) acts … believe it or not … as the foundation for later searching!


Splitting … and even more splitting  … 

So, as mentioned earlier, I start by splitting my Scent Detecting training into three separate, but interconnected, phases;

  1. Familiarising my dog to the target odour.
  2. Training the passive indication.
  3. Searching.

… but, my splitting doesn’t end there! Each of these three phases will be split further.

For example, the apparently simple phase of familiarising my dog to the odour – which takes approximately 30 minutes to conclude – is split, again, into the following elements;

  1. Introduction to the environment – Physical and Psychological. If you’d like to know a little bit more about this particular element, follow this link to Scent Detecting and the Enriched Environment
  2. Choice of equipment – Harness and Line.
  3. Rewards – Food vs Toys (play?). Quantity. Timing. Look out for my forthcoming Blog post – Food, Glorious Food.
  4. Selection of the Target Odour – Safety. Cost and Availability. Previous use. Single Odour vs Configural Odour. Quantity (Concentration) of Odour. There’ll be more guidance in my forthcoming Blog post – Selecting a Training Odour for your Scent Detecting Dog. Some Considerations.
  5. Mechanics of Training – Classical (Pavlovian) conditioning. Development of a positive Conditioned Emotional Response (CER).

The devil is, very definitely, in the detail.


… and then there’s Back Chaining

According to Orr (2015), back chaining is a really effective way to build reliable behaviours. It’s a very efficient way to teach a specific behaviour, limits any potential errors and “leads to fluency with less training time” (Pryor, 2012).

Scent Detecting requires a whole series of individual behaviours that, together, form a particular behaviour chain. My dogs’ Scent Detecting behaviour chain looks something like this;

Cue to start work (Context. Harness. Scent in the Environment. Word) → Searching the Area → Locates the Target Scent Source → Passive Indication → Verbal Cue to move away from the scent source → Leaves the Scent Source → Click → Returns to me → Rewards

Your dog’s Scent Detecting behaviour chain may look very different to mine. It all depends on your training approach and your particular requirements … but I’m sure you get the idea; it’s complex and, for success, careful, thorough, training is required.

I teach Scent Detecting by starting at the end of the behaviour chain and working my way back to the beginning. As Orr (2015) states, “by teaching the last part first the learner [my dog] is always moving toward the part of the skill that he learned first and with which he is most confident“. For my dogs, this means learning about the target odour first – the familiarisation process.


Familiarising your dog to the target odour – the mechanics

Familiarising your dog to a specific (target) odour involves Classical, or Pavlovian,  Conditioning. It’s about helping your dog form positive associations with the scent. What starts out as a completely irrelevant odour to your dog, or neutral stimulus (NS), will, after conditioning, start to predict that good things (rewards) will follow (McLeod, 2013).

Familiarisation does not mean leaving the target scent with your dog (amongst his bedding, perhaps) for a few weeks until he becomes “used to”, or “familiar with”, it … unfortunately, “mere exposure [has] no effect on the acquisition of an odor discrimination in dogs” (Hall et al, 2014). If only it were that simple.

Scent : Detect : Find uses a very adapted form of Hall et al’s (2014) familiarisation protocol. Unit 13 is not a laboratory! Firstly, your dog is introduced to his “working” environment – he’s allowed to explore (or not) as he wishes – and then the familiarisation process begins. Over a 20 – 30 minute time-frame, as your dog continues to investigate the environment, he’s given the opportunity to “sniff” the target odour followed, immediately, with food rewards. No other behaviour is required … no need to sit, stand, down or similar. This procedure is repeated approximately 6 – 10 times within the 20 – 30 minute time period.

As for the “sniff” … well … some trainers place huge emphasis on hearing the dog inhale – sniff – during this familiarisation process … nothing less will do. This view probably has its origins in the work of Craven et al (2010) who state that, during normal respiration, approximately 12-13% of inspired air will reach the chemosensory area of the nose – the ethmoturbinate region – and that during active sniffing this may increase by 2-3%.

I’m not worried about hearing your dog sniff. That 12-13% of normally inspired air will do just fine for me! Why? Well let me give you an everyday – olfactory – example. If you walk along a road … breathing normally … you’re likely to become aware of a multitude of different odours, from the smell of bad drains, to the odour of frying chips, to diesel fumes, to … no need to sniff. Interestingly, you’re only going to start sniffing when you encounter a very faint hint of an odour, one that you’re trying to identify and locate. As Mainland and Sobel (2006) state, “when the olfactory system encounters a concentrated odorant, sniff vigor is reduced in real time; when it encounters a diluted odorant, sniff vigor is increased in real time“. In short, as your dog explores the environment, he’ll be aware of the target odour regardless of whether he chooses to sniff or not!

So, back to the familiarisation process and classical conditioning.

Before Conditioning – if your dog is offered food, an unconditioned stimulus (US), he’ll begin to salivate. It’s a physiological process resulting in an unconditioned response (UR). He just can’t help it.

Food (US) —> Salivation (UR)

Initially, if you let your dog smell what will eventually become his target odour, it’ll mean nothing to him. It’s a neutral stimulus (NS).

Target Odour (NS) —> No Salivation

During Conditioning – this requires you to allow your dog to smell the target odour and then provide him with food.

Target Odour (NS) —> Food (US) —> Salivation (UR)

After Conditioning – the target odour is now a conditioned stimulus (CS) and is associated with food. Smelling the odour in his environment will cause your dog to salivate in expectation of food rewards. Salivation in response to the target odour is now a conditioned response (CR).

Target Odour (CS) —> Salivation (CR)

According to Hall et al (2014), familiarising your dog to the target odour in this way enhances odor discrimination training and may reduce the overall training time. In short, it’s a worthwhile exercise to work through especially as it only takes approximately 30 minutes to complete.

Interestingly, and importantly, by classically conditioning your dog to the target odour, it will become what Berridge et al (2009) describe as, a “motivational magnet” – something that has to be approached, often compulsively. This is the foundation of all subsequent searching behaviour. Your dog WANTS to find the target odour. As Berridge et al (2009) explain, WANTING can apply both to unconditioned stimuli (US) such as food as well as conditioned stimuli (CS) such as the target odour after a classical conditioning procedure has taken place such as the one described here.

According to Litman (2005), WANTING involves dopamine activation in the brain and is thought to “motivate approach behaviour and to attribute incentive value to stimuli associated with reward” … the target odour!

But not only will your dog WANT to find the target odour, he’ll LIKE it too. After classical conditioning, your dog will have formed a positive conditioned emotional response (CER) to the target odour. As Litman (2005) states, LIKING involves brain opioid activity and “consequent states of pleasure“. Your dog will LIKE the target odour and WANT to find it. This phenomenon – your dog’s desire to get to the target odour – is sometimes referred to as Scent Obedience.


Familiarising your dog to the target odour and the notion of Imprinting

For clarity, in some scent detecting circles, the process of Familiarising your dog to the target odour (as described here, but often using very different training protocols) is frequently referred to as Imprinting. I prefer to avoid using this term in the context of scent detecting as it has its origins within the field of Ethology and is associated with the work of Konrad Lorenz and the rearing of Geese. Beware, terminology can be confusing and misleading!


and in conclusion …

If you’d like your scent detecting to progress a little more smoothly, consider splitting your training to avoid the lumps. Start where you’d like to finish – Back Chain!


Final Note

As with all of my blogs, I include a reference list. This allows you to investigate the topic a little further, check out the sources of my information and decide for yourself whether my interpretations of the literature represent an accurate reflection of the author’s work. Happy reading.


© Lesley McAllister – Scent : Detect : Find Ltd 2020

www.scentdetectfind.co.uk


References / Further Reading

  1. Berg J (2018) Lumping and splitting. Science. 359. 6382. 1309
  2. Berridge KC, Robinson TE and Aldridge JW (2009) Dissecting components of reward; ‘Liking’, ‘Wanting’ and Learning’. Current Opinion in Pharmacology. Feb. 9(1): 65-73
  3. Craven BA, Paterson EG and Settles GS (2010) The fluid dynamics of canine olfaction: unique nasal airflow patterns as an explanation of macrosmia. Journal of the Royal Society. Interface. 7. 933-943
  4. Hall NJ, Smith DW, Wynne CDL (2014) Effect of odor preexposure on acquisition of an odor discrimination in dogs. Learning and Behavior. Jan
  5. Horowitz A and Hecht J (2014) Chapter 9. Looking at Dogs: Moving from Anthropocentrism to Canid Umwelt. IN: Horowitz A (2014) Ed. Domestic Dog Cognition and Behavior. The Scientific Study of Canis Familiaris. Springer.
  6. Litman JA (2005) Curiosity and the pleasures of learning: Wanting and liking new information. Cognition and Emotion. 19(6). 793-814
  7. Mainland J and Sobel N (2006) The Sniff is part of the Olfactory Percept. Chem. Senses. 31: 181-196
  8. McLeod S A (2013) Pavlov’s Dogs. http://www.simplypsychology.org/pavlov.html accessed; 22.12.2015
  9. Orr J (2015) Back Chaining: The top secret teaching tool that is the key to professional success. TAGteach International. https://tagteachblog.com/back-chaining-the-top-secret-teaching-tool-that-is-the-key-to-professional-success/ 
  10. Pryor K (2012) Back-Chaining “Retrieve”. Karen Pryor Clicker Training. https://www.clickertraining.com/back-chaining-retrieve Accessed: 3.8.2020
  11. Zerubavel E (1996) Lumping and Splitting: Notes on Social Classification. Sociological Forum. 11.3. 421-423.

The Indication. It’s not an optional extra!

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Poppy clearly indicating the location of her target scent inside this person’s trouser pocket.

What is an Indication?

The indication or alert is the means by which your dog is able to communicate to you that he’s found the location of his target scent source. It’s a behaviour that, after training, your dog will perform “immediately and unprompted” (Cablk et al, 2006) and is usually categorised as being either passive or (pro)-active in nature. In large part this classification is dependent on the degree to which the indication behaviour involves contact, or direct interaction with, the scent source.

I tend to view passive indications as those where the dog makes minimal or no contact with the scent source. For example, your dog might sit or lie down beside the scent source or place his nose on it or simply stare at it. In contrast, the pro-active indication involves far more direct engagement with the scent source and may include behaviours such as scratching, grabbing, biting and retrieving (Hurt et al, 2009).

Barking is another very commonly used indication. As this behaviour doesn’t involve any direct contact with the scent source, it would seem to be just another type of  passive indication, however, as Hurt et al (2009) point out, as a fundamentally frustrative behaviour that “can accelerate into other frustration behaviors” it is probably better described as a pro-active indication. In explaining their position, Hurt et al (2009) cited the case of search dogs on the Island of Guam who were trained to detect brown tree snakes and indicate their location by barking. Unfortunately, before very long, this behaviour transformed into pawing and biting and, for the safety of the dogs and the welfare of the snakes, the dogs had to be re-trained.


Does my Scent Detecting dog need an indication?

My short answer to this question is YES and here’s why …

Successful Scent Detecting requires your dog to search for, and locate, his target scent source. Without an indication (either passive or pro-active), you’ll have no means of knowing – for sure – that he’s found it. As Scent Detecting is primarily all about finding, it makes little sense to overlook training the one unambiguous way that your dog has to tell you that he has done just that … his indication.


Why spend time training an indication when I can just watch for a COB?

Recently I’ve noticed a growing trend toward relying on a dogs change of behaviour (COB) to help the handler recognise that their dog has located the scent source. Typical changes in behaviour might include slowing down, speeding up, heightened interest in a particular area of a room, walking on tip-toes with head held high … the list of possibilities is almost endless. Each of these behaviours may help you narrow down the location of the target scent source but may also act to totally mislead you.

As an example of just how poor a COB can be as a means of helping you decide that your dog has located the target scent source, take a little look at this video of Dream working amongst farm machinery.

 

At 23 seconds Dream starts to show a heightened interest along the wall of the tractor shed. This extra interest, or COB – standing on tip-toes, head in the air, staying close to the wall, carefully investigating certain areas – continues until approximately 58 seconds into the video when she then moves on to investigate other parts of the building.

I think it perfectly reasonable to suggest that many handlers, seeing their dog showing this level of interest in a particular area, would be sorely tempted to keep their dog working there until something is ‘found’. That something being a false indication.

Put simply;

The dog’s COB → Increased interest in the area by the handler → Increasing interest in the area by the dog → Further interest in the area by the handler → Increasing psychological pressure on dog to ‘find’ something → False (positive) indication by the dog!

This is just one example of  the ‘Clever Hans Phenomenon’ or ‘Clever Hans Effect’ at work – “where a person or animal can be influenced by subtle and unintentional cueing on the part of a questioner” (Jackson, 2005). If you’d like to know more about how the Clever Hans phenomenon can impact your scent detecting, just follow this link to False Indications, Clever Hans and You

At “Scent : Detect : Find” dogs are trained to search independently, following scent plumes and filaments back to source without undue interference from their human partners. This “hands off” approach to scent detecting goes a long way toward mitigating the Clever Hans Phenomenon. In addition, all dogs are trained an indication behaviour that is totally reliable and unambiguous …. so much so that it is easily recognisable, not only to the handler but, to anyone else who might be looking on.

If you review the video again, you’ll notice that throughout her search Dream’s handler remains out of shot. At all times, Nicky gives Dream the necessary space to work independently. Even when Dream shows heightened interest along the wall of the tractor shed (23 secs – 58 secs), Nicky stays clear of the area and waits for Dream to persuade her, by way of her indication, that her target scent source is there … or, as in this particular search … in a completely different area!

And this is why your dog’s indication is not an optional extra. Having a well trained indication allows Nicky to simply watch her dog until that indication comes.

… Nose Touch. Stillness. Duration.


So, what type of Indication is best – Passive or Pro-Active?

I favour the passive indication and train my own, and other handlers, dogs to place their nose as close to the target scent source as possible and hold it there for a minimum of 5 seconds or until their handler asks them to move away.

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Chewee accurately indicating the location of his target scent; a tiny sticky dot.

This type of indication fits well with your dog’s natural olfactory behaviour. Watch your dog when he’s pottering around the garden. What does he do when he catches an interesting odour? He gets his nose as close to it as possible and, more often than not, will stay fixed to it for a lengthy period of time.

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The Passive “nose touch” Indication; a very natural olfactory behaviour

If the scent source is inaccessible to your dog’s nose, for example, placed high up on a wall, or submerged under-water, then this nose touch is transformed easily and quickly into a sustained nose point.

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Bob using his nose to point to his target scent.

 

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Fynn pointing to his submerged target scent.

My reasons for selecting the passive indication and, more particularly, the

nose touch → nose point (if inaccessible)

include;

Safety – Passive indications help minimise any direct engagement with the target scent source. This can be important where either the target scent itself, or its location, may pose a danger to your dog.

For example, tobacco products such as cigarette and cigar butts, nicotine patches and gum and e-cigarette fluid are all harmful to our dogs (Novotny et al, 2011).

Whilst the target scent may be safe for your dog, its location may not be. Sadly, every year there are a number of reported dog fatalities from Acute Water Intoxication following a period of time playing in water (Toll et al, 1999). Typically, these dogs have been repeatedly diving into water to retrieve items thrown in for them whilst, at the same time, ingesting excessive volumes of water (Becker, 2013). Although the actual prevalence of this condition is difficult to confirm – Becker (2013) believing it to be a relatively rare occurrence – retrieving from water should be an activity that you monitor closely and / or consider restricting.

If your dog has a passive indication, all of these potential dangers are markedly reduced.

Precise and unambiguous – There is no mistaking the precise location of the target scent when your dog’s nose is either touching or pointing toward it. Adding duration to the indication adds even more certainty … your dog isn’t simply having a passing investigatory sniff!

Other passive indications such as a sit or a down cannot match this degree of accuracy particularly in situations where your dog is searching for tiny amounts of target scent, so tiny that you would be hard pressed to see it yourself.

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Brook using her nose to indicate on an invisible target scent

Can be used in all situations – No matter where the target scent is located – submerged under water, high up on a piece of furniture, buried underground, in an easily accessible position – it will be possible for your dog to either touch his nose to it or point toward its position.

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Abel using his nose touch to indicate “buried treasure”!

Preserves the integrity of the scent source – A nose touch, or point, minimises any possible damage to the target scent source. This is unlikely to be the case with a Pro-active indication.

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Luytje pointing out a bundle of cash whilst leaving it completely intact!

Requires no further training or re-training in changed circumstances – Starting off your Scent Detecting training with a pro-active indication may seem like a good idea at the time … until you decide to introduce a new target odour. It may be potentially dangerous to you or your dog or very valuable. Ooops … now may be the time to start afresh with your training, this time with a passive indication.


But a Passive Indication is difficult and time-consuming to train, isn’t it?

Well, that all depends on your point of view …

It certainly requires careful, detailed and thorough training to ensure reliability. Training can take anything from just a few hours or, in a limited number of cases (and for some very specific reasons), a few months to complete and this should all happen BEFORE searching “proper” begins.

Without this careful, early, training you are likely to encounter indication problems further down the line. Far simpler to train a reliable passive indication in the first place than have to add in further, often complex, remedial training at some later point in time including “Show me” or “Where is it?” cues.

The “Show me” or “Where is it?” cue is used, predominantly, within competition scent work circles where TIME means POINTS means PLACES! For very obvious reasons, an indication with lengthy duration is rarely trained and, as a consequence, any indication that there is may be missed by the handler. The “Show me” cue is a way of asking the dog to return to the location of the target scent and indicate again. I’m afraid I’m not a great fan of this sticking plaster approach to training. Far better I’d say to train the indication behaviour thoroughly in the first place than add in this extra layer of training complexity.

And then there’s the thorny issue of being “just a pet dog owner”. According to this viewpoint, pet dog owners are rarely interested in training a reliable passive indication. … It takes time … It delays their dog from starting to search until the indication training is complete … They aren’t bothered about an indication … They don’t have the training skills … and so on. Certainly this has never been my experience. The vast majority of my clients are “just pet dog owners” with almost 60 of them having trained reliable passive indications and another 50 or more well on their way.

If you are “just a pet dog owner” … keep this in mind … In a study by McCulloch et al (2006), investigating the ability of dogs to detect early- and late-stage lung and breast cancer, it was a mix of pet dogs with only basic puppy training who (in a matter of weeks) were able to accurately identify breath samples from lung and breast cancer patients. Those of you who are “just pet dog owners” can, and do, achieve great things with your dogs.


So … in conclusion …

As Scent Detecting is all about finding, it makes little sense to overlook training the one unambiguous way that your dog has to tell you that he has done just that … his indication.

If you’d like to know how I train a Passive Indication, look out for a future Blog – one of a series of three – Smoothing out the Lumpy Bits; Why it might be wise to teach the indication before the search and all that back chaining stuff 

And  … NO … your dog’s indication should never be a scent detecting optional extra.


Final Note

As with all of my blogs, I include a reference list. This allows you to investigate the topic a little further, check out the sources of my information and decide for yourself whether my interpretations of the literature are an accurate reflection of the author’s original work. Happy reading.


© Lesley McAllister – Scent : Detect : Find Ltd 2018

www.scentdetectfind.co.uk

https://www.facebook.com/scentdetectfind/?ref=bookmarks


References / Further Reading

  1. Becker K (2013) Water Intoxication: Too Much of a Good Thing. https://healthypets.mercola.com/sites/healthypets/archive/2013/10/28/water-intoxification.aspx Accessed 15.12.2018
  2. Cablk ME and Heaton JS (2006) ACCURACY AND RELIABILITY OF DOGS IN SURVEYING FOR DESERT TORTOISE (GOPHERUS AGASSIZII). Ecological Applications. 16(5). 1926-1935
  3. Hurt A and Smith DA (2009). Conservation Dogs. IN: Helton WS (Ed) Canine Ergonomics: The Science of Working Dogs. Taylor and Francis Group: London.
  4. Jackson J (2005) The Clever Hans effect – a horse’s tale. Critical Thinking. http://www.critical-thinking.org.uk/pdf/clever-hans.pdf
  5. McCulloch M, Jezierski T, Broffman M, Hubbard A, Turner K and Janecki T (2006) Diagnostic Accuracy of Canine Scent Detection in Early- and Late-Stage Lung and Breast cancers. Integrative Cancer Therapies. 5(1). 30-39
  6. Novotny TE, Hardin SN, Hovda LR, Novotny DJ, McLean MK, Khan S (2011) Tobacco and cigarette butt consumption in humans and animals. Tobacco Control. 20. 17-20
  7. Toll J, Barr SC, Hickford FH (1999) Acute Water Intoxication in a Dog. Journal of Veterinary Emergency and Critical Care. 9. 1. 19-22.

The Heat Is On: Summer Temperatures and Our Scent Detecting Dogs

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It’s hot out there!

Please Note

The focus of this Blog is our dogs’ normal thermoregulatory mechanisms and how these might impact on their Scent Detecting activities during the warmer summer months. If you feel that your dog is struggling in any way with the heat, SEEK IMMEDIATE QUALIFIED VETERINARY ASSISTANCE.


With day-time temperatures in the UK currently reaching anything between 25°C and 30ºC, social media has seemingly gone into overdrive with dire warnings of the dangers this heat may pose to our dogs. Owners are being advised to curtail all usual activities in a bid to keep their dogs cool and many sporting events have been cancelled or postponed. But what about our scent detecting dogs? Can they continue to work in these high temperatures or should we keep them in the shade until the cooler weather returns?

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Should we retire our Scent Detecting dogs until the temperature drops?

Some background …

Without sweat glands, panting (with accompanying evaporative cooling from the upper respiratory tract) is the main means by which our dogs are able to maintain their normal body temperature of between 37.5°C and 39.1°C (Gazit et al, 2003. Jordan et al, 2016). Any deviations from this narrow range can interfere with normal cellular function (Bear et al, 2016) and, in extreme cases, may result in death.

Our dogs are considered thermally stable when any extra heat they gain is matched by the equivalent amount of heat loss (Stanley, 1980). The thermoneutral zone (TNZ) is the environmental temperature range (between 20°C – 30°C) at which our dogs can maintain their normal body temperature without having to expend energy to either increase heat production or heat loss (Jordan et al, 2016).

The total heat load our dogs experience is made up of both environmental and metabolic factors. If the ambient temperature exceeds our dogs’ body temperature then they will absorb heat from the environment (Jordan et al, 2016). While the heat produced by our dogs’ organs remains fairly constant, heat production by their skeletal muscle is dependent on their activity levels. Up to 80% of our dogs’ body heat is produced by their working muscles (Stanley, 1980).


A little bit of anatomy and physiology … well … quite a lot actually!

Cold– and Warm-sensitive neurons, found in the pre-optic area of the anterior hypothalamus of our dogs’ brains, detect (and respond to) changes in circulating blood temperature. In the case of any rise in temperature, there is a reduction in the release of Thyroid Stimulating Hormone (TSH) from the anterior pituitary gland resulting in a slowing down of our dogs’ metabolism. Blood is shunted toward our dogs’ peripheries to help dissipate heat through the skin and you might start to notice some behavioural changes including a desire to seek shady areas. In addition, our dogs involuntary motor response is to pant (Bear et al, 2016. Hardy et al, 1964).


If you’d like to find out a little more about the hypothalamus and the pre-optic area … just follow these three links.

https://www.neuroscientificallychallenged.com/blog/2014/5/10/hypothalamus-know-your-brain?rq=hypothalamus

https://www.neuroscientificallychallenged.com/blog/2-minute-neuroscience-hypothalamus-and-pituitary-gland?rq=hypothalamus

https://www.neuroscientificallychallenged.com/blog/know-your-brain-preoptic-area?rq=Temperature%20regulation


Goldberg, et al (1981) have identified three patterns of breathing exhibited by dogs’ as their need for evaporative cooling increases either because of increasing environmental temperature or exercise load. As previously mentioned, up to 80% of our dogs’ body heat is produced by working skeletal muscle!

  • Pattern I – Inhalation and Exhalation through the nose.
Panting I
Pattern I – Inhalation and Exhalation through the nose

This pattern of breathing is characteristic of the resting dog and, in Goldberg, et als (1981) study was observed in dogs who were either resting in environmental temperatures below 26°C or running at slow speeds in cooler temperatures (10°C).

As inhaled air travels to the lungs, it is warmed and humidified by the moist nasal mucosa. In turn, the nasal mucosa is cooled. On exhalation, air loses its heat to the now, cooler, nasal mucosa and water condenses. This counter-current heat exchange system helps our dogs conserve heat and moisture that might otherwise be lost to the external environment.

In contrast, when our dogs’ need to lose heat, this heat-exchange mechanism can be circumvented by a) vasodilation of the nasal mucosa between inhalation and exhalation and b) switching to exhalation through the mouth as in Patterns II and III.

  • Pattern II – Inhalation through the nose. Exhalation through the nose and mouth.
Panting - II.jpg
Pattern II – Inhalation through the nose. Exhalation through the nose and mouth

Goldberg, et al (1981) observed this pattern of breathing in dogs either resting quietly in environmental temperatures ranging between 30°C and 42°C or during exercise (except when running slowly at low temperatures as in Pattern I). In these types of environmental and exercise conditions, dogs breathing was seen to oscillate between patterns II and III.

The dogs normal, resting, respiratory rate of between 10-35 breaths / minute (average 24 breaths / minute) increases to approximately 250 breaths / minute. Interestingly, this panting frequency matches the active sniffing frequency of the scent detecting dog (3-7Hz = 3-7 sniffs / second). Panting and active sniffing frequencies are thought to minimise energy expenditure (Craven et al, 2010. Settles et al, 2002).

Although our dogs can now by-pass the heat exchange system in the nose and increase heat loss by exhaling through their mouths, heat loss still occurs mainly in the nose. Vasodilation of the nasal mucosa, with extra moisture being provided by two lateral nasal glands (Steno’s glands) which open through ducts just inside our dogs’ noses, increases evaporative cooling. As breathing rate increases, so does secretion of fluid from these glands (Blatt, et al, 1972).

  • Pattern III – Inhalation through the nose and mouth. Exhalation through the nose and mouth.
Panting - III.jpg
Pattern III – Inhalation and Exhalation through the nose and mouth

This pattern of breathing is seen in situations of severe heat stress. The amount of time our dogs use this pattern of breathing increases alongside increases in environmental temperature and exercise load. According to Goldberg, et al (1981), exercise will increase our dogs heat load more so than an increasing environmental temperature.

Lingual blood flow (blood flow to the tongue) increases during moderate heat stress alongside Salivation. Saliva production is governed by the hypothalamus as one of its thermoregulatory responses. Evaporative cooling takes place as dry air is inhaled across the moist tongue and mouth.

Unfortunately, although these three respiratory patterns can be useful signposts to us with regard to how our dogs are coping with the environmental temperature or exercise, Baker, et al (1989) warn that dehydrated dogs will reduce thermoregulatory evaporation in order to reduce water loss. In short, a dehydrated dog will have a lower respiratory rate with a consequent higher body temperature as panting is reducedBaker, et al (1989) observed a rapid recovery of panting in their study dogs after they were able to drink water.


So … What does all of this mean for our Scent Detecting dogs?

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Our dogs cannot sniff and pant at the same time

Our dogs’ ability to detect their target odour is largely dependent on their ability to sniff  (Mainland et al, 2006). During normal breathing, approximately 12-13% of inspired air will reach the chemosensory area of our dogs noses – the olfactory epithelium – but, importantly, active sniffing will increase this amount by another 2-3% (Craven et al, 2010).

In high temperature environments or, after strenuous physical activity, our dogs’ need to divert attention away from the scent detecting task (and active sniffing) and toward maintaining their body temperature within normal limits (Gazit et al, 2003). As previously discussed, this requires our dogs to pant.

Unfortunately, when our dogs pant, not only are they NOT actively sniffing but “a large turbulent jet is expired from the mouth, obscuring any scent-bearing air currents in the vicinity. The dog must therefore normally stop panting in order to sniff” (Settles et al, 2002). Our dogs cannot sniff and pant at the same time!

In Gazit et als (2003) study investigating explosives detection by sniffer dogs working in hot climates, they found a decrease in “olfactory efficiency [resulting] mainly from overheating [which caused] physiological and behavioural resources to be diverted from concentration on the assigned task and applied instead to methods of body cooling”. Interestingly, however, after training in, and exposure to, high temperature working environments, their scent detecting performance improved. This is likely to have been due to the process of acclimatization whereby the animal becomes physically adjusted to, and able to tolerate, the temperature of their environment (University of Iowa: Hospitals and Clinics, 2016). Amongst other things, acclimatization to heat decreases the temperature threshold at which heat dissipation mechanisms are activated (Bruchim et al, 2014. Horowitz, 1998); Our dogs’ “cooling strategies” come into play much sooner than they would pre-acclimatization.

According to Horowitz (1998), “heat acclimation is switched on in response to persistent, moderate ambient heat and takes time to develop but is long acting (several weeks)”. Partial acclimatization may take from 10 – 20 days while full acclimatization may take up to 60 days (Jordan et al, 2016). Certainly, from a personal perspective, this rings true for me. Now, a number of weeks into these unusually high UK temperatures, my own dogs are far more active than they were in the early days of this ongoing heatwave.


So … Should we retire our Scent Detecting dogs until the temperature drops? 

With a little care, thought and planning, Summer Scent Detecting is still perfectly possible, however, each of us must decide for ourselves whether it is safe to proceed.


A few points to keep in mind

  1. Our dogs pant in response to an increasing body temperature – we need to keep Scent Detecting sessions short and, wherever possible, work in areas with plenty of shade / protection from the sun.
  2. Panting is an involuntary motor response which helps our dogs’ maintain their body temperature within normal limits – they cannot choose to stop panting and continue sniffing. Scent Detecting activities may take longer than expected as our dogs pant rather than sniff. Ensure plenty of “down-time” and allow our dogs’ to take extra breaks whenever they want to.
  3. Our dogs will cease to pant (and overheat) if they are dehydrated – Ensure a plentiful supply of fresh drinking water at all times. Do not “force” a dog to drink.
  4. Remember that up to 80% of our dogs’ body heat is produced by their working skeletal muscles – Scent Detecting may be a far safer activity for our dogs in high temperature environments than other, more strenuous, sports and hobbies. No dog should be forced to exercise.
  5. Take extra care if you own any of the brachycephalic breeds, eg; pug – the anatomy of their head is likely to interfere with their ability to pant and regulate their temperature (Stanley, 1980).
  6. Our dogs’ can acclimatize to high ambient temperatures but it takes time – Do not expect our dogs’ to be working as enthusiastically, or at as fast a speed, as they would normally during the cooler months.

Happy Scent Detecting!

 


Final Note

As with all of my blogs, I include a reference list. This allows you to investigate the topic a little further, check out the sources of my information and decide for yourself whether my interpretations of the literature accurately reflect the author’s work. Happy reading.


© Scent : Detect : Find Ltd 2018


References / Further Reading

  1. Baker M A and Turlejska E (1989) Thermal panting in dehydrated dogs: effects of plasma volume expansion and drinking. European Journal of Physiology. 413. 511-515.
  2. Bear M F, Connnors B W and Paradiso M A (2016) Neuroscience. Exploring the Brain. 4th Ed. Philadephia: Wolters Kluwer.
  3. Blatt C M, Taylor C R and Habal M B (1972) Thermal Panting in Dogs: The Lateral Nasal Gland, a Source of Water for Evaporative Cooling. Science. 804-805.
  4. Bruchim Y, Aroch I, Eliav A, Abbas A, Frank I, Kelmar E, Codner C, Segev G, Epstein y and Horowitz M (2014) Two years of combined high-intensity physical training and heat acclimatization affect lymphocyte and serum HSP70 in purebred military working dogs. Journal of Applied Physiology. 117. 112-118.
  5. Craven B A, Paterson E G and Settles G S (2010) The fluid dynamics of canine olfaction: Unique nasal airflow patterns as an explanation of macrosmia. Journal of the Royal Society. Interface. 7. 933-943.
  6. Gazit I and Terkel J (2002) Explosives detection by sniffer dogs following strenuous physical activity. Applied Animal Behaviour Science. 81. 149-161.
  7. Goldberg M B, Langman V A and Taylor C R (1981) Panting In Dogs: Paths Of Airflow In Response To Heat and Exercise. Respiration Physiology. 43. 327-338.
  8. Hardy J D, Hellon R F and Sutherland K (1964) Temperature-Sensitive Neurones in the Dog’s Hypothalamus. Journal of Physiology. 175. 242-253.
  9. Horowitz M (1998) Do Cellular Heat Acclimation Responses Modulate Central Thermoregulatory Activity? News Physiological Science. 13. 218-225.
  10. Jordan M, Bauer A E and Croney C (2016) Temperature Requirements for Dogs. Are they tailored to promote dog welfare? Purdue Extension. October. 1-3.
  11. Mainland J and Sobel N (2006) The Sniff is part of the Olfactory Percept. Chem. Senses. 31. 181-196.
  12. Settles G S, Kester D A and Dodson-Dreibelbis L J (2002) The External Aerodynamics of Canine Olfaction. IN: Barth F G, Humphrey J A C and Secomb T W (Eds) Sensors and Sensing in Biology and Engineering. New York: Springer.
  13. Stanley S M (1980) A Study of Heat Stroke and Heat Exhaustion in the Dog. Iowa State University Veterinarian. 42. 24-27.
  14. University of Iowa: Hospitals and Clinics (2016) Acclimatization: Adjusting to the Temperature. https://uihc.org/health-topics/acclimatization-adjusting-temperature. Accessed 1.8.2018

The Tortoise and The Hare … and we all know who won that particular race!

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Showing a clean pair of heels

It’s hard not to be impressed by the dog who speeds around the search area appearing totally engaged with the task in hand as he tries to locate his target scent. In comparison, the dog who moves more slowly is often overlooked in favour of his flashier counterpart. But, where scent detecting is concerned, speed might not be everything and selecting the right breed for the job may be more a matter of taste than a matter of science.

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Speed isn’t everything

In the UK, the most commonly selected breeds for scent detecting work include (amongst others) Labradors, Spaniels, Border Collies, German Shepherds and Malinois. But which breed is best?

Gadbois and Reeve (2014) favour the Border Collie, basing their preference, amongst other things, on the breed’s apparent persistence and good sniffing ability. They propose that certain breeds have higher baseline levels of dopamine than others which, they state, “raises the intriguing possibility that baseline dopamine levels may have a direct impact on cognition, motivation, learning, and overall olfactory behaviour and performance”. They refer to this possibility as their “dopamine hypothesis” and link this to the notion of “work ethic”. Other breeds they single out as “dopamine dogs” include Belgian Malinois and Jack Russell Terriers. More about dopamine in a future blog.

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Gadbois and Reeve (2014) favour the Border Collie. Floss in action.

All that said, Hall, et al (2015) and Rooney and Bradshaw (2004) argue that the choice of working dog may have far more to do with historical precedent than any real evidence of superior scent detecting ability. According to Johnen, et al (2017), good quality empirical studies remain thin on the ground and as Jamieson, et al (2017) warn, “continually selecting the same dog breeds, without inspecting other breeds, may reduce the effectiveness of detection dog programs”.

Interestingly, in McCulloch, et als (2006) study investigating the ability of dogs to detect early- and late-stage lung and breast cancer, it was a mix of pet dogs (rather than ‘working’ dogs) with only basic puppy training who (in a matter of weeks) were able to accurately identify breath samples from lung and breast cancer patients.

Hall, et al (2015) argue for the need for “direct behavioural measurement of assumed behavioural breed differences”. Contrary to all expectations, in their 2015 study comparing the scent detecting abilities of German Shepherds, Greyhounds and Pugs, the Pugs significantly outperformed both other breeds.

pug
The Pug … a surprisingly good scent detecting breed?

Whilst Hall, et als (2015) study may not have persuaded you to purchase your first scent detecting pug … well, not yet anyway … it does raise another important question. Did the Pugs succeed because of their superior olfactory ability or because of the training methods employed in the study?

In an attempt to address this question, Polgar, et al (2016) developed a simple strategy to measure differences in olfactory ability that did not require any pre-training. Raw turkey meat was placed under 1 of 4 ceramic pots. Five levels of difficulty were arranged by way of decreasing numbers of holes in the ceramic pots. Subjects were assigned to one of four groups; dog breeds selected for their scent detecting abilities, dog breeds selected for other purposes, dog breeds with short noses and hand-reared grey wolves. The dogs / wolves were led along the row of pots to identify, by scent alone, which contained the meat. Dog breeds selected for scent detecting work out-performed both the short nosed breeds and those bred for other purposes. At the most difficult level, wolves and the scenting breeds performed better than chance.

Interestingly, according to Maejima, et al (2007), “research with drug detection dogs failed to reveal any significant link between performance and theoretically relevant genotypes” however, Lesniak, et al (2008) argue that breed and heredity may have some influence on scent detecting ability … “there may be a relation between a certain genotype at a particular locus and the ability of more accurate scent detection of particular volatile organic compounds”. This raises the intriguing possibility that not only may some breeds (or individuals within a breed) have better olfactory abilities than others but that some breeds (or individuals within a breed) may have better olfactory abilities when tasked to detect particular target scents.

Similarly, we also show variation in our ability to detect certain odours. Odour sensitivity is heritable. One well referenced example of this “specific anosmia” relates to the ability to detect a sulphurous odour in urine following asparagus consumption (Pelchat, et al (2011)). Some of us can smell it, some of us can’t. Could our dogs also have “specific anosmias”?

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Asparagus – Can you smell it?

Returning then to the original subject of this blog. Tortoise or Hare? Accuracy or speed? According to Helton (2009) “a dog may quickly find substances, but may miss targets because of haste. A dog may also be very slow to find substances, but based on a methodical approach may miss few or no targets”. Self-evidently, a dog whose performance is both accurate and fast seems hugely desirable and, as Helton (2009) suggests, “training and practice can markedly improve skill” … a combination of speed and accuracy, perhaps?

But, can training and practice really alter your dog’s general “approach” (or speed) to scent detecting work? Can you turn your slow and thoughtful Rottie into a speedy working Cocker? Experience would suggest not. Each breed (and every dog within that breed) comes with its own, highly individual, set of characteristics; a mixture of heredity and past life experiences. Far better to work with the dog you have in front of you than attempt to turn him into something he can never be. For me, one of the big enjoyments of working with so many different breeds is their very different styles of working. Each and every one of them brings something new to scent detecting and helps break down any stereotypical views of what different breeds might be capable of. Tortoise or Hare … I’ll take both please!

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Slow and thoughtful Jim
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Speedy Brook

 

 

 

 

 

 

 

 

So, a thought to leave you with. When Helton, et al (2009) asked a trainer which breed was best as an explosives detector dog, his reply was … “depends on where you live, you see here in the United States it is the Labrador Retriever, in the United Kingdom it is the Springer Spaniel, in Belgium it is the Belgian Malinois, in Germany the German Shepherd, and in Norway, they are pushing the Norwegian Drever, a dog most people have never heard of. Personally, I think it is all goofy, pick any dog you are comfortable with”.

And, if you think a Norwegian Drever might be the scent detecting dog for you … just follow this link … https://www.skk.se/en/NKU-home/nordic-dog-breeds/sweden/drever/

© Lesley McAllister – Scent : Detect : Find Ltd 2018

References / Further Reading

  1. Gadbois S and Reeve C (2014) Canine Olfaction: Scent, Sign, and Situation. IN: Horowitz A (Ed) Domestic Dog Cognition and Behavior. The Scientific Study of Canis Familiaris. London: Springer.
  2. Hall N J, Glenn K, Smith D W and Wynne D L (2015) Performance of Pugs, German Shepherds and Greyhounds (Canis Lupus Familiaris) on an Odor Discrimination Task. Journal of Comparative Psychology. 129(3). 237-246.
  3. Helton W S (2009) Overview of Scent Detection Work. Issues and Opportunities. IN: Helton W S (Ed) Canine Ergonomics. The Science of Working Dogs. London: Taylor and Francis Group.
  4. Helton W S, Feltovich P J and Velkey A J (2009) Skill and Expertise in Working Dogs. A Cognitive Science Perspective. IN: Helton W S (Ed) Canine Ergonomics. The Science of Working Dogs. London: Taylor and Francis Group.
  5. Jamieson L T J, Baxter G S and Murray P J (2017) Identifying suitable detection dogs. Applied Animal Behaviour Science. 195. 1-7.
  6. Johnen D, Heuwieser W and Fischer-Tenhagen C (2017) An approach to identify bias in scent detection dog testing. Applied Animal Behaviour Science. 189. 1-12.
  7. Lesniak A, Walczak M, Jezierski T, Sacharczuk M, Gawkowski M and Jaszczak K (2008) Canine Olfactory Receptor Gene Polymorphism and Its Relation to Odor Detection Performance by Sniffer Dogs. Journal of Heredity. 99 (5). 518-527
  8. Maejima M, Inoue-Murayama M, Tonosaki K, Matsuura N, Kato S, Saito Y, Weiss A, Murayama Y and Ito S (2007) Traits and genotypes may predict the successful training of drug detection dogs. Applied Animal Behaviour Science. 107. 3-4. 287–298.
  9. McCulloch M, Jezierski T, Broffman M, Hubbard A, Turner K and Janecki T (2006) Diagnostic Accuracy of canine Scent Detection in Early- and Late-Stage Lung and Breast Cancers. Integrative Cancer Therapies. 5(1). 30-39
  10. Pelchat M L, Bykowski C, Duke F F and Reed D R (2011) Excretion and Perception of a Characteristic Odor in Urine after Aspragus Ingestion: a Psychophysical and Genetic Study. Chemical Senses. 36. 1. 9-17.
  11. Polgar Z, Kinnunen M, Ujvary D and Gacsi M (2016) A Test of Canine Olfactory Capacity. Comparing Various Dog Breeds and Wolves in a Natural Detection task. Plos One. May. 1-14.
  12. Rooney N J and Bradshaw J W S (2004) Breed and sex differences in the behavioural attributes of specialist search dogs – a questionnaire survey of trainers and handlers. Applied Animal Behaviour Science. 86. 123-135.