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3-5-2019
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Scents of Success
The extraordinary olfactory abilities of dogs have long been used by humans for odor identification and discrimination. Our use of this incredible canine tool, which we are completely unable to imitate or engineer, is continuously expanding. We deploy the canine nose for life-and-death activities such as improving our safety (e.g., bomb and drug detection, tracking lost individuals, avalanche work) and our health (e.g., cancer detection, diabetes/seizure alert). We also use the dog’s exceptional scenting ability for recreation as we hunt game and play novel games involving scent detection (e.g., nose/scent work, utility obedience, tracking, hunt tests/field trials).
Given the importance of the dog’s superlative schnoz, it’s important to understand what factors might alter its function. What about physical stressors such as exercise, conditioning, diet and environment?
Several studies provide important information about what dogs need to be at their scenting best and reveal clues about how we can optimize olfaction!
Factors That Can Affect Scents-Ability in Dogs
1. Conditioning
Some people are surprised that conditioning can affect a dog’s scenting ability. I mean, what does the strength of a dog’s muscles have to do with the ability of odor molecules to land on the receptors in the nose and transmit a neurological signal to the brain? However, fitness is one of the most important factors in your dog’s odor detection ability. In one study, dogs that were less fit had an astounding 64% reduction in their scent sensitivity compared to physically conditioned dogs (1)! Another showed a higher frequency of correct target alerts in physically fit dogs (2). This might be related to the lower heart rate in conditioned dogs and therefore a reduction in the need for panting (which reduces olfaction because of reduced airflow through the nose).
2. Diet
There are just a few studies of the effects of diet on scenting ability in dogs, but they offer some fascinating insights into the potential for improving scenting ability through appropriate nutrition. English Pointers withheld from exercise and fed a diet supplemented with coconut oil appeared to experience compromised olfaction, but exercised dogs maintained their olfactory acuity (3) – another reason to keep your dog fit!
Another study showed benefits to olfaction when using a corn oil-supplemented diet and exercise – there’s that fitness component again (1)! A third study looked at “the breakfast effect” in which dogs searched more accurately 30 min following the consumption of breakfast than when fasted. They concluded that food might provide energy for cognitive processes, and that search accuracy in fasted dogs decreased as a function of energy depletion (4).
3. Environment
Factors that lead to heat stress including lack of acclimatization to a novel environment, increased environmental temperature, increased humidity, lack of access to water, and/or poor ventilation, all contribute to reduced odor detection ability (5). A dog that is heat stressed will pant, which itself reduces olfaction due to reduced airflow through the nose. In addition, dehydration can significantly decrease odor detection capabilities in dogs (3).
4. Age
Older dogs can have age-related changes in their scenting system, similar to that experienced by aged people (6). Older dogs had a reduced number of odor-detecting cells in their noses and the cells that remained had a reduced number of cilia (the tiny hairs that contain odor receptors, which grab odor molecules out of the air). Scent detection games can provide excellent environmental stimulation for old dogs, though, so don’t let this possible deficiency stop you from providing your oldster with odoriferous experiences. Just make sure the odors are strong!
5. Drugs
There is a long list of pharmaceuticals that can cause reduced olfaction in humans including anesthetics, antiarrhythmics, antihistamines, antimicrobials, antiproliferative and immuno-suppressive drugs, endocrine drugs, gastrointestinal (GI) drugs, neurologic drugs, and NSAIDs (7, 8, 9). The list of drugs that have been proven to affect scenting ability in dogs is shorter because of a lack of research. Those include some cardiac drugs, high doses of metronidazole, steroids, and chemotherapeutics (10). Regardless, it is important to consider that any dog being treated with a pharmaceutical might have diminished scenting ability.
6. Subclinical or Chronic Diseases
Interestingly, endocrine conditions such as hypothyroidism, diabetes and Cushing’s disease can cause a lack of scenting ability in dogs (11). The mechanism for this is unknown, but given that many dogs live with these chronic conditions, it is important to ensure that the dog is getting the best current therapy for the condition, which should minimize the risk of effects on olfaction. If your dog is living with one of these conditions, consider that they might be less efficient at scenting.
It might seem worrisome that there are so many factors that can affect your dog’s scents-ability, but the good news is that, with a little knowledge and forethought, you can substantially reduce the risk of odor detection deficiencies and even help your dog establish and maintain superlative scenting skills!
Given the importance of the dog’s superlative schnoz, it’s important to understand what factors might alter its function. What about physical stressors such as exercise, conditioning, diet and environment?
Several studies provide important information about what dogs need to be at their scenting best and reveal clues about how we can optimize olfaction!
Factors That Can Affect Scents-Ability in Dogs
1. Conditioning
Some people are surprised that conditioning can affect a dog’s scenting ability. I mean, what does the strength of a dog’s muscles have to do with the ability of odor molecules to land on the receptors in the nose and transmit a neurological signal to the brain? However, fitness is one of the most important factors in your dog’s odor detection ability. In one study, dogs that were less fit had an astounding 64% reduction in their scent sensitivity compared to physically conditioned dogs (1)! Another showed a higher frequency of correct target alerts in physically fit dogs (2). This might be related to the lower heart rate in conditioned dogs and therefore a reduction in the need for panting (which reduces olfaction because of reduced airflow through the nose).
2. Diet
There are just a few studies of the effects of diet on scenting ability in dogs, but they offer some fascinating insights into the potential for improving scenting ability through appropriate nutrition. English Pointers withheld from exercise and fed a diet supplemented with coconut oil appeared to experience compromised olfaction, but exercised dogs maintained their olfactory acuity (3) – another reason to keep your dog fit!
Another study showed benefits to olfaction when using a corn oil-supplemented diet and exercise – there’s that fitness component again (1)! A third study looked at “the breakfast effect” in which dogs searched more accurately 30 min following the consumption of breakfast than when fasted. They concluded that food might provide energy for cognitive processes, and that search accuracy in fasted dogs decreased as a function of energy depletion (4).
3. Environment
Factors that lead to heat stress including lack of acclimatization to a novel environment, increased environmental temperature, increased humidity, lack of access to water, and/or poor ventilation, all contribute to reduced odor detection ability (5). A dog that is heat stressed will pant, which itself reduces olfaction due to reduced airflow through the nose. In addition, dehydration can significantly decrease odor detection capabilities in dogs (3).
4. Age
Older dogs can have age-related changes in their scenting system, similar to that experienced by aged people (6). Older dogs had a reduced number of odor-detecting cells in their noses and the cells that remained had a reduced number of cilia (the tiny hairs that contain odor receptors, which grab odor molecules out of the air). Scent detection games can provide excellent environmental stimulation for old dogs, though, so don’t let this possible deficiency stop you from providing your oldster with odoriferous experiences. Just make sure the odors are strong!
5. Drugs
There is a long list of pharmaceuticals that can cause reduced olfaction in humans including anesthetics, antiarrhythmics, antihistamines, antimicrobials, antiproliferative and immuno-suppressive drugs, endocrine drugs, gastrointestinal (GI) drugs, neurologic drugs, and NSAIDs (7, 8, 9). The list of drugs that have been proven to affect scenting ability in dogs is shorter because of a lack of research. Those include some cardiac drugs, high doses of metronidazole, steroids, and chemotherapeutics (10). Regardless, it is important to consider that any dog being treated with a pharmaceutical might have diminished scenting ability.
6. Subclinical or Chronic Diseases
Interestingly, endocrine conditions such as hypothyroidism, diabetes and Cushing’s disease can cause a lack of scenting ability in dogs (11). The mechanism for this is unknown, but given that many dogs live with these chronic conditions, it is important to ensure that the dog is getting the best current therapy for the condition, which should minimize the risk of effects on olfaction. If your dog is living with one of these conditions, consider that they might be less efficient at scenting.
It might seem worrisome that there are so many factors that can affect your dog’s scents-ability, but the good news is that, with a little knowledge and forethought, you can substantially reduce the risk of odor detection deficiencies and even help your dog establish and maintain superlative scenting skills!
References
1. Angle CT, Wakshlag JJ, Gillette RL, Steury T, Haney P, Barrett J, Fischer T. The effects of exercise and diet on olfactory capability in detection dogs. J Nutr Sci 2014;3:e44 Read the PDF
2. Gazit I, Terkel J. Explosives detection by sniffer dogs following strenuous physical activity. Appl Anim Behav Sci 2003;81:149-61 Read the PDF
3. Altom EK, Davenport GM, Myers LJ, Cummins KA. Effect of dietary fat source and exercise on odorant-detecting ability of canine athletes. Research in Veterinary Science 2003;75:149–155 Read the PDF
4. Miller HC, Bender C. The breakfast effect: Dogs (Canis familiaris) search more accurately when they are less hungry. Behav Proc 2012;91:313-317 Read the PDF
5. Andress M, Goodnight ME. Heatstroke in a military working dog. US Army Med Dep J 2013;1:34-7
6. Hirai T, Kojima S, Shimada A. Age-related changes in the olfactory system of dogs. Neuropathol Appl Neurobiol 1996;22(6):532-9
7. Bromley SM. Smell and taste disorders: a primary care approach. Am Fam Physician 2000;61:427-36
8. McNeill EJM, Carrie S. Olfactory dysfunction – assessment and management J ENT Masterclass 2009;2:68-73
9. Scott AE. Clinical characteristics of taste and smell disorders. Ear Nose Throat J 1989;68:297-298,301,304-21
10. Jenkins EK, Lee-Fowler TM, Angle TC, Behrend EN, Moore GE. Effects of oral administration of metronidazole and doxycycline on olfactory capabilities of explosives detection dogs. Am J Vet Res 2016;77:906-12.
11. Myers LJ. Dysosmia of the dog in clinical veterinary medicine. Prog Vet Neurol 1990;1:171-9
2. Gazit I, Terkel J. Explosives detection by sniffer dogs following strenuous physical activity. Appl Anim Behav Sci 2003;81:149-61 Read the PDF
3. Altom EK, Davenport GM, Myers LJ, Cummins KA. Effect of dietary fat source and exercise on odorant-detecting ability of canine athletes. Research in Veterinary Science 2003;75:149–155 Read the PDF
4. Miller HC, Bender C. The breakfast effect: Dogs (Canis familiaris) search more accurately when they are less hungry. Behav Proc 2012;91:313-317 Read the PDF
5. Andress M, Goodnight ME. Heatstroke in a military working dog. US Army Med Dep J 2013;1:34-7
6. Hirai T, Kojima S, Shimada A. Age-related changes in the olfactory system of dogs. Neuropathol Appl Neurobiol 1996;22(6):532-9
7. Bromley SM. Smell and taste disorders: a primary care approach. Am Fam Physician 2000;61:427-36
8. McNeill EJM, Carrie S. Olfactory dysfunction – assessment and management J ENT Masterclass 2009;2:68-73
9. Scott AE. Clinical characteristics of taste and smell disorders. Ear Nose Throat J 1989;68:297-298,301,304-21
10. Jenkins EK, Lee-Fowler TM, Angle TC, Behrend EN, Moore GE. Effects of oral administration of metronidazole and doxycycline on olfactory capabilities of explosives detection dogs. Am J Vet Res 2016;77:906-12.
11. Myers LJ. Dysosmia of the dog in clinical veterinary medicine. Prog Vet Neurol 1990;1:171-9
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2-5-2019
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To Harness or Not To Harness? That is the Question
… that was addressed by a recent study that is the topic of this month’s newsletter. You’ve probably noticed an upsurge during the last several years in the use of harnesses as an alternative to collars. At the same time, there has been a concern that harnesses might affect dogs’ gait. Researchers in the UK investigated exactly that question by comparing the effect of restrictive and non-restrictive harnesses on shoulder extension in dogs when walking and trotting (1).
There are two main categories of harnesses: those that are considered non-restrictive to front limb movement, which have a Y-shaped chest strap (Fig. 1), and those considered restrictive, which have a strap that lies across the chest horizontally (Fig. 2).
There are two main categories of harnesses: those that are considered non-restrictive to front limb movement, which have a Y-shaped chest strap (Fig. 1), and those considered restrictive, which have a strap that lies across the chest horizontally (Fig. 2).
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Figure 1. Example of a non-restrictive harness. These have a Y-shaped component that should lie over the manubrium (front of the sternum).
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Figure 2. Example of a restrictive harness. These generally have a horizontal strap that runs over the shoulder joint or the scapula (shoulder blade) and across the chest/neck of the dog.
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In this study, 9 dogs were moved at a walk and a trot on a treadmill wearing either no harness, a non-restrictive harness (an X-back mushing harness; Trixie Fusion harness), or a restrictive harness (Easy Walk harness). The researchers placed markers on the sides of the dogs’ legs and used video cameras to measure the angle of the shoulder when the front limb was in maximal extension (when the leg was placed furthest forward).
Some of their results were unexpected!
Results of the Study: No harness vs. non-restrictive harness vs. restrictive harness
The researchers also examined the effect of weights added to the harness to try to simulate the dog pulling against the harness. The weights were used in a way that caused the harness to be pulled up and away from the dog’s back at an approximately 45o angle, similar to how the harness would be pulled on if a person were walking behind the dog.
Results of the Study: Weights vs. No Weights
The authors are to be commended for performing this important study and for their excellent discussion of the results.
One limitation of the study mentioned by the authors was that their system was not designed to measure step or stride length or stance time, which can affect shoulder extension. However, a previous harness study did look at those parameters (2). That study showed that both non-restrictive and restrictive harnesses alter step and stride length as compared to the same dogs wearing just a collar.
Questions, Questions…
Some of their results were unexpected!
Results of the Study: No harness vs. non-restrictive harness vs. restrictive harness
- Dogs wearing only a collar had significantly more shoulder extension, both while walking and trotting, than dogs wearing either type of harness.
- Dogs wearing non-restrictive harnesses had significantly less shoulder extension than dogs wearing restrictive harnesses when both walking and trotting. That was the unexpected finding, and we’ll look at those results more closely in a minute.
The researchers also examined the effect of weights added to the harness to try to simulate the dog pulling against the harness. The weights were used in a way that caused the harness to be pulled up and away from the dog’s back at an approximately 45o angle, similar to how the harness would be pulled on if a person were walking behind the dog.
Results of the Study: Weights vs. No Weights
- Dogs walking using non-restrictive harnesses with weights had significantly less shoulder extension than dogs wearing non-restrictive harnesses without weights or than those wearing restrictive harnesses with or without weights.
- Dogs trotting using non-restrictive harnesses with weights had significantly less shoulder extension than dogs wearing restrictive harnesses with or without weights.
The authors are to be commended for performing this important study and for their excellent discussion of the results.
One limitation of the study mentioned by the authors was that their system was not designed to measure step or stride length or stance time, which can affect shoulder extension. However, a previous harness study did look at those parameters (2). That study showed that both non-restrictive and restrictive harnesses alter step and stride length as compared to the same dogs wearing just a collar.
Questions, Questions…
1. Why would the so-called non-restrictive harness reduce shoulder extension more than the restrictive harness?
A: In my opinion, it might be a function of harness fit. As you can see in Figure 3 (taken from the publication but with arrows added), the non-restrictive harness is not ideally fitted to the dog. The straps that lie in front of the scapula (shoulder blade) are pressing into the dog’s body (arrows), almost certainly preventing the dog from moving its scapula forward. This, of course, would limit shoulder extension.
A non-restrictive harness needs to be fitted so that it is tight around the dog’s neck. That way, when the dog is pulling, the Y-shaped chest strap applies pressure to the manubrium (the front of the sternum), and the straps on the side of the neck should not slide back to lie against the shoulder blade. For most dogs, this means that the neck part of the harness needs to be adjustable and needs to have a clip, so that it doesn’t have to be large enough to slip over the dog’s head.
2. Why would the addition of weights to the non-restrictive harness further reduce the dog’s shoulder extension?
A: See answer to question 1. I think that when the weights pulled on the harness, those loose side straps pulled even harder against the dog’s shoulder blades, further restricting shoulder extension.
3. Why would the addition of weights to the restrictive harness allow the dog to have more shoulder extension?
A: It is likely that the weights pulling upwards and backwards on the restrictive harness allowed the horizontal band to rise up on the dog’s front, taking some of the pressure of that band off of the shoulder joint (Fig. 4). This would allow the dog to extend its shoulder further (although it might put more pressure on the dog’s neck).
A: In my opinion, it might be a function of harness fit. As you can see in Figure 3 (taken from the publication but with arrows added), the non-restrictive harness is not ideally fitted to the dog. The straps that lie in front of the scapula (shoulder blade) are pressing into the dog’s body (arrows), almost certainly preventing the dog from moving its scapula forward. This, of course, would limit shoulder extension.
A non-restrictive harness needs to be fitted so that it is tight around the dog’s neck. That way, when the dog is pulling, the Y-shaped chest strap applies pressure to the manubrium (the front of the sternum), and the straps on the side of the neck should not slide back to lie against the shoulder blade. For most dogs, this means that the neck part of the harness needs to be adjustable and needs to have a clip, so that it doesn’t have to be large enough to slip over the dog’s head.
2. Why would the addition of weights to the non-restrictive harness further reduce the dog’s shoulder extension?
A: See answer to question 1. I think that when the weights pulled on the harness, those loose side straps pulled even harder against the dog’s shoulder blades, further restricting shoulder extension.
3. Why would the addition of weights to the restrictive harness allow the dog to have more shoulder extension?
A: It is likely that the weights pulling upwards and backwards on the restrictive harness allowed the horizontal band to rise up on the dog’s front, taking some of the pressure of that band off of the shoulder joint (Fig. 4). This would allow the dog to extend its shoulder further (although it might put more pressure on the dog’s neck).
Figure 3. This shows the experimental set-up for dogs using non-restrictive harnesses in the Lafuente study. The white lines show how the angle of maximum shoulder extension was measured. The yellow arrows show the harness pressing into the dog’s body in front of the scapula, which likely would prevent the shoulder blade from freely sliding forward when the dog is wearing this harness, This would reduce the angle of shoulder extension.
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Figure 4. This shows the experimental set-up for dogs using restrictive harnesses in the Lafuente study. The yellow arrow indicates the direction in which the harness might move when a weight that pulls upward and backward at a 45o angle is attached to the harness. This would reduce pressure on the shoulder joint, but might put increased pressure on the dog’s neck.
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Bottom Line:
- Harnesses are still a safer option for dogs that have tracheal collapse, laryngeal paralysis, obstructive airway disease or neurological problems involving the neck, such as wobblers disease.
- Because two studies now provide good evidence that both restrictive and non-restrictive harnesses alter dogs’ gaits, a collar might be a better choice for many dogs. However, dogs wearing collars should be trained to walk politely, without pulling, on a leash. An excellent booklet that shows how to do this is My Dog Pulls. What Do I Do? By Turid Rugaas (3).
- If you choose to use a non-restrictive harness, make sure it is tightly fitted around the dog’s neck so that it doesn’t slide back and put pressure on the dog’s shoulders.
- If you choose to use a restrictive harness, make sure it is loosely fitted, so that it can slide away from the dog’s shoulder as needed.
References
1. Lafuente MP, Provis L, Schmalz EA. Effects of restrictive and non-restrictive harnesses on shoulder extension in dogs at walk and trot. Vet Record 2018;1-7. doi: 10.1136/vr.104946 Read the PDF
2. Carr BJ, Dresse K, Zink MC. The effects of five commercially available harnesses on
canine gait. Proceedings of ACVS Surgical Summit, 2016. Read the PDF
3. Rugaas T. My Dog Pulls. What Do I Do? 2005. Dogwise Publishing.
2. Carr BJ, Dresse K, Zink MC. The effects of five commercially available harnesses on
canine gait. Proceedings of ACVS Surgical Summit, 2016. Read the PDF
3. Rugaas T. My Dog Pulls. What Do I Do? 2005. Dogwise Publishing.
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1-1-2019
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How to Make Your Dog More Optimistic
Research across many species, from rats to dogs to zoo animals, show that their attitude towards life, positive or negative, affects their welfare, mental health, ability to learn and remember, and the quality of their decisions. Negative attitudes are often tied to separation anxiety or dog-directed fear and aggression. So, we want our dogs to have a positive attitude not only because it makes them happier but also because it increases mental stability, improves how easily their learn, remember, and make good decisions about situations they find themselves in. Read on to find out how one of the newest dog sports improves dogs’ optimism and with it, all of these benefits.
Cognitive Bias
We all know people who are ‘glass half-full’ types – they look at life from a positive viewpoint and generally are fun to be with. And of course, there are the ‘glass half-empty’ types, who always seem pessimistic and can be kind of a downer to spend time with.
This attitude toward life is referred to as cognitive bias (also called judgment bias), and it has huge implications for mental health, as well as learning and memory. Cognitive bias has a significant influence on behavior and decision-making. In fact, changing a person’s cognitive bias is a core feature of cognitive behavioral therapy, one of the most well-founded therapeutic interventions for improving mental health.
Cognitive bias is measured in humans using a language-based test. Cognitive bias testing in animals consists of training the animal to discriminate between two stimuli: one associated with a positive event (e.g. food reward), the other associated with a negative event, such as disgusting food, a fear-eliciting object, or the absence of a reward. The animal is then given an ambiguous stimulus and its behavior observed.
Cognitive bias testing has shown that rats living in unpredictable living conditions expect less positive outcomes than rats living in predictable conditions (1). Sheep that are released from restraint have a more positive cognitive bias (2). Pigs in an enriched environment are more optimistic than pigs in a less enriched environment (3). Even honeybees demonstrate cognitive bias – those from hives that were shaken were more likely to drink from flowers containing a liquid that contained less sugar than those from a stable hive (4).
Cognitive Bias Testing In Dogs
To test cognitive bias in dogs, a dog is seated about 10’ (3m) from a 6’ (2m) line placed perpendicular to the dog and owner (see figure). When a bowl is placed at one end of the line (the positive end), it contains great food. When placed at the other end of the 6’ line (the negative end), it is empty. Then an empty bowl is placed in the middle of the 6’ line and the dog is observed to see how many seconds it takes to approach the bowl (5).
Cognitive Bias
We all know people who are ‘glass half-full’ types – they look at life from a positive viewpoint and generally are fun to be with. And of course, there are the ‘glass half-empty’ types, who always seem pessimistic and can be kind of a downer to spend time with.
This attitude toward life is referred to as cognitive bias (also called judgment bias), and it has huge implications for mental health, as well as learning and memory. Cognitive bias has a significant influence on behavior and decision-making. In fact, changing a person’s cognitive bias is a core feature of cognitive behavioral therapy, one of the most well-founded therapeutic interventions for improving mental health.
Cognitive bias is measured in humans using a language-based test. Cognitive bias testing in animals consists of training the animal to discriminate between two stimuli: one associated with a positive event (e.g. food reward), the other associated with a negative event, such as disgusting food, a fear-eliciting object, or the absence of a reward. The animal is then given an ambiguous stimulus and its behavior observed.
Cognitive bias testing has shown that rats living in unpredictable living conditions expect less positive outcomes than rats living in predictable conditions (1). Sheep that are released from restraint have a more positive cognitive bias (2). Pigs in an enriched environment are more optimistic than pigs in a less enriched environment (3). Even honeybees demonstrate cognitive bias – those from hives that were shaken were more likely to drink from flowers containing a liquid that contained less sugar than those from a stable hive (4).
Cognitive Bias Testing In Dogs
To test cognitive bias in dogs, a dog is seated about 10’ (3m) from a 6’ (2m) line placed perpendicular to the dog and owner (see figure). When a bowl is placed at one end of the line (the positive end), it contains great food. When placed at the other end of the 6’ line (the negative end), it is empty. Then an empty bowl is placed in the middle of the 6’ line and the dog is observed to see how many seconds it takes to approach the bowl (5).
Now, you might be thinking, “Of course the dog will approach the bowl to see whether a great treat might be waiting there!” But a recent study showed that dogs that scored higher on traits such as sociability, excitability and lower in non-social fear ran more quickly towards the ambiguous bowl and thus were considered to have a more optimistic bias than dogs with separation anxiety or dog-directed fear and aggression, who were judged to be more pessimistic (6).
Cognitive Bias in Dogs Trained in Nosework vs. Heeling
A recently published study used cognitive bias testing to compare dogs that had been trained in nosework vs. heeling (7). Here is how they did the study. Twenty dogs were trained in the cognitive bias test, so they knew where to go to get the good treat, and they knew that the other bowl was empty. The dogs were then randomly assigned to groups of 10 dogs each and both groups of dogs were tested for their cognitive bias by placing the bowl in the ambiguous position and the amount of time it took them to get to the bowl was recorded. There were no differences between the groups in this initial test.
Then one group of dogs spent two weeks being trained in nosework, while the other group was trained in heeling. Both groups of dogs spent the same amount of time training with their owners, the same amount of time being active, and ingested the same quantity of food during training. The groups were then re-tested for cognitive bias. The outcome measure was how many seconds it took the dogs to go to the ambiguous bowl after training as compared to before training.
Results
Dogs that had been trained in nosework approached the ambiguous bowl significantly faster than they did before whereas there was no difference for the dogs trained in heeling. The authors concluded that the dogs that were trained in nosework had a more “optimistic” outlook. They postulate that pet dogs generally cannot engage in natural behaviors such as foraging, which free-range dogs spend 10 to 22% of their time doing. They quote a number of studies that demonstrate that foraging is a natural behavior of many species including dogs and is a form of environmental enrichment important for animal welfare.
Conclusion
So how cool is this? Playing scenting games with our dogs, such as nosework, makes
their cognitive bias more positive. Future research will have to confirm the final
outcomes but if dogs are like other species, that more positive attitude will make them
more optimistic about life, increase their mental stability, improve how easily they learn
and remember, and improve their decision making.
Comments
OK, I know what you’re thinking – the dogs that were trained in nosework were clearly trained to look into boxes for food, so of course they went more quickly towards the ambiguous bowl in hopes of finding food. Well, it should be noted that the dogs in both groups were just as effective in identifying, and approaching or not, the positive and negative bowls during the cognitive bias testing – only their behavior towards the ambiguous bowl differed. That suggests that there wasn’t an effect of being trained to go and investigate bowls.
This study suggests that foraging (looking for and consuming food) is stimulating and intrinsically rewarding to dogs. Thus, increasing your dog’s foraging time, whether that means teaching nosework or scent work formally or just as a game to play around the house and yard, or using food-distributing toys might actually increase your dog’s optimism and outlook toward life.
And just as an extra note: oxytocin has been found to improve cognitive bias in dogs too (8). So all that time you spend petting, making eye contact, and telling your dog you love him/her (which has been shown to induce secretion of oxytocin in both human and dog) – that’s improving both your AND your dog’s outlook on life! I’m all for that
Cognitive Bias in Dogs Trained in Nosework vs. Heeling
A recently published study used cognitive bias testing to compare dogs that had been trained in nosework vs. heeling (7). Here is how they did the study. Twenty dogs were trained in the cognitive bias test, so they knew where to go to get the good treat, and they knew that the other bowl was empty. The dogs were then randomly assigned to groups of 10 dogs each and both groups of dogs were tested for their cognitive bias by placing the bowl in the ambiguous position and the amount of time it took them to get to the bowl was recorded. There were no differences between the groups in this initial test.
Then one group of dogs spent two weeks being trained in nosework, while the other group was trained in heeling. Both groups of dogs spent the same amount of time training with their owners, the same amount of time being active, and ingested the same quantity of food during training. The groups were then re-tested for cognitive bias. The outcome measure was how many seconds it took the dogs to go to the ambiguous bowl after training as compared to before training.
Results
Dogs that had been trained in nosework approached the ambiguous bowl significantly faster than they did before whereas there was no difference for the dogs trained in heeling. The authors concluded that the dogs that were trained in nosework had a more “optimistic” outlook. They postulate that pet dogs generally cannot engage in natural behaviors such as foraging, which free-range dogs spend 10 to 22% of their time doing. They quote a number of studies that demonstrate that foraging is a natural behavior of many species including dogs and is a form of environmental enrichment important for animal welfare.
Conclusion
So how cool is this? Playing scenting games with our dogs, such as nosework, makes
their cognitive bias more positive. Future research will have to confirm the final
outcomes but if dogs are like other species, that more positive attitude will make them
more optimistic about life, increase their mental stability, improve how easily they learn
and remember, and improve their decision making.
Comments
OK, I know what you’re thinking – the dogs that were trained in nosework were clearly trained to look into boxes for food, so of course they went more quickly towards the ambiguous bowl in hopes of finding food. Well, it should be noted that the dogs in both groups were just as effective in identifying, and approaching or not, the positive and negative bowls during the cognitive bias testing – only their behavior towards the ambiguous bowl differed. That suggests that there wasn’t an effect of being trained to go and investigate bowls.
This study suggests that foraging (looking for and consuming food) is stimulating and intrinsically rewarding to dogs. Thus, increasing your dog’s foraging time, whether that means teaching nosework or scent work formally or just as a game to play around the house and yard, or using food-distributing toys might actually increase your dog’s optimism and outlook toward life.
And just as an extra note: oxytocin has been found to improve cognitive bias in dogs too (8). So all that time you spend petting, making eye contact, and telling your dog you love him/her (which has been shown to induce secretion of oxytocin in both human and dog) – that’s improving both your AND your dog’s outlook on life! I’m all for that
References
1. Harding EJ, Paul ES, Mendl M. Cognitive bias and affective state. Nature 2004;427:312. Read the PDF
2. Doyle RE, Fisher A, Hinch GN, Biossy A, Lee C. Release from restraint generates a positive judgment bias in sheep. Appl Anim Behav Sci 2010;122:28-34. Read the PDF
3. Asher L, Friel M, Griffin K, Collins LM. Mood and personality interact to determine cognitive biases in pigs. Biology Letters 2016;12:20160402. Read the PDF
4. Bateson M, Desire S, Gartside SE, Wright GA. Agitated honeybees exhibit pessimistic cognitive biases. Current Biology 2011;21(12):1070-1073. Read the PDF
5. Bethell EJ. A “how-to” guide for designing judgment bias studies to assess captive animal welfare. J Appl Anim Wel Sci 2015;18(sup1):S18-S42. Read the PDF
6. Barnard S, Wells DL, Milligan ADS, Arnott G, Hepper PG. Personality traits affecting judgement bias task performance in dogs (Canis familiaris). Nature 2018;8:6660. Read the PDF
7. Duranton C, Horowitz A. Let me sniff! Nosework induces positive judgment bias in pet dogs. Appl Anim Behav Sci 2018;Dec. 3. Read the PDF
8. Kis A, Hernadi A, Kanizsar O, Gacsi M, Topal J. Oxytocin induces positive expectations about ambivalent stimuli (cognitive bias) in dogs. Hormone Behav 2015;69:1-7. Read the PDF
2. Doyle RE, Fisher A, Hinch GN, Biossy A, Lee C. Release from restraint generates a positive judgment bias in sheep. Appl Anim Behav Sci 2010;122:28-34. Read the PDF
3. Asher L, Friel M, Griffin K, Collins LM. Mood and personality interact to determine cognitive biases in pigs. Biology Letters 2016;12:20160402. Read the PDF
4. Bateson M, Desire S, Gartside SE, Wright GA. Agitated honeybees exhibit pessimistic cognitive biases. Current Biology 2011;21(12):1070-1073. Read the PDF
5. Bethell EJ. A “how-to” guide for designing judgment bias studies to assess captive animal welfare. J Appl Anim Wel Sci 2015;18(sup1):S18-S42. Read the PDF
6. Barnard S, Wells DL, Milligan ADS, Arnott G, Hepper PG. Personality traits affecting judgement bias task performance in dogs (Canis familiaris). Nature 2018;8:6660. Read the PDF
7. Duranton C, Horowitz A. Let me sniff! Nosework induces positive judgment bias in pet dogs. Appl Anim Behav Sci 2018;Dec. 3. Read the PDF
8. Kis A, Hernadi A, Kanizsar O, Gacsi M, Topal J. Oxytocin induces positive expectations about ambivalent stimuli (cognitive bias) in dogs. Hormone Behav 2015;69:1-7. Read the PDF
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