Tag Archives: sniffing dogs

Sniffing out error in detection dog data

A new study in the journal Scientific Reports gets to the bottom of it: Why do dogs that are trained to locate poop sometimes find the wrong kind of poop?

Sniffer dog reseawrcgh

Washington University researcher Karen DeMatteo and her scat-sniffing dog Train are on a mission to preserve jaguars, pumas, bush dogs and other carnivores in the forests of Northeastern Argentina. (Photo: courtesy of Karen DeMatteo/Washington University)

It happens anywhere from 4 percent to 45 percent of the time, said Karen DeMatteo, a biologist in Arts & Sciences at Washington University in St. Louis. Her new research confirms that there are three viable, alternative explanations beyond errors in handler or dog training that can explain the collection of non-target scats with detection dogs in some ecosystems.

Detection dogs are trained to use scent, not their eyes, to locate specific kinds of scat. They’re useful partners in conservation projects as an alternative to camera photo traps or other more invasive means of identifying which individual animals are present in an area.

And while finding the wrong kind of poop doesn’t ultimately muck up research results — researchers who use scat to track animals usually use DNA tests to confirm the identity of target and non-target evacuators — collecting and testing false positives costs a project time and resources.

“To date, when non-target samples are found in detection dog studies, it is assumed it may be due to errors in detection dog or handler training; however, our study determined that this is not always the case,” DeMatteo said. “Instead, the complexity of ecosystems where a study is conducted can affect the perceived accuracy of detection dog studies because the natural behaviors of non-target species, like coyotes in our study, can alter the genetic profile of target scat, like that from a puma.”

In her own work, DeMatteo has successfully used scat-detection dogs to identify the routes traveled by endangered pumas and other reclusive carnivores along a biologically important corridor in Argentina.

Detection dogs are great at determining the presence of specific animals because they can find droppings hidden in grass, droppings that have been rained on and disintegrated into the mud — or even droppings that have been eaten and then recycled.

Yes, that’s right, and it’s a normal part of life for many animals, DeMatteo said.

“Humans have a natural aversion to coprophagy, which is reflected in the visual horror on an owner’s face when they see their dog gobble down their own scat or the scat of another dog or cat,” DeMatteo said. “Once this shock subsides, the owner typically worries that the scat will cause health problems or there is something psychologically wrong with their four-legged friend.”

“While the reasons underlying coprophagy in domestic dogs are still fuzzy, it is known in wild canids that coprophagy is natural and is often associated with territoriality or nutritional benefits,” she said. “So while the finding that coyotes will consume puma scat is novel and has various ecological implications, coprophagy occurs naturally under a variety of circumstances.”

The tendency of one animal to eat another’s scat is one of three behaviors that might alter the type of scat, or the state of the scat, that a detector dog might encounter, and thus affect the perceived accuracy of the technique.

Researchers also considered how urine-marking by non-target species might affect a detector dog’s ability to locate scat from a species of interest, and also what happens if one animal picks up another’s scat and moves it using its mouth, potentially bringing it into contact with saliva. Field trials were conducted in the St. Louis area and in northwest Nebraska.

The researchers found that each of the proposed behaviors alters the genetic profile of the scat in question, and all were confirmed to play a role in the detection dog indicating on non-target scats.

The pool of conservation-trained detection dogs is constantly growing in number, as are the types of target species and the areas where they are being used, DeMatteo said. One of the continuing questions surrounding their use for these types of projects is how to maintain a high quality standard for training detection dogs and their handlers.

“In reality, the dog is easier to train than the handler, with the latter having a higher chance of introducing error,” DeMatteo said. “Even with these variables, these results are extendable to other dog-handler teams with less experience, as long as consistency is used.”

While this study, “How behavior of nontarget species affects perceived accuracy of scat detection dog surveys,” demonstrates that there are alternative explanations for why dogs sometimes collect non-target samples, it also shines a light on behaviors that humans may not understand — but that could play a role in ecosystem functioning.

“Genetic testing can eliminate these samples and maintain accuracy in the [detection dog-assisted] studies,” DeMatteo said. “However, this non-target interaction with target scat potentially has important implications for other ecological questions, including parasite/disease transmission, zoonotic diseases and general health of wild populations.”

 

Source:  Washington University in St Louis media statement

 

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New sniffer dog research

A team of scientists has provided the first evidence that dogs can learn to categorise odours and apply this to scents they have never encountered before.

The research reveals how the animals process odour information and is likely to have a profound impact on how we train sniffer dogs.

Sniffer dog research
Training a sniffer dog (photo courtesy of University of Lincoln)

The study, led by researchers at the University of Lincoln, UK, and funded by the Office of Naval Research and the Office of Naval Research (ONR) Global in the US,
found that dogs are able to categorise odours on the basis of their common properties. This means that dogs can behave towards new smells from a category in the same way as smells that they already know.

As humans, we do not have to experience the smell of every fish to know that it smells ‘fishy’; instead we use our previous experience of fish and categorise the new smell in the correct way. The new research, published in the journal Scientific Reports, reveals that dogs can do the same.

Researchers separated dogs into two groups and then trained them to respond to 40 different olfactory stimuli – or smells – half of which were accelerant-based. The dogs in the experimental group were trained (through a reward) to offer a behavioural response, for example “sit”, when they were presented with smells which fit a specific category, but to withhold that response for other non-category stimuli. The remaining dogs were trained on the same stimuli but were not rewarded for the categorical variable.

The researchers found that only the dogs in the category group were able to learn the task. Even more significantly, when presented with completely unknown smells, the dogs were able to place them in the correct category and to remember the odours six weeks later.

The researchers concluded that this means that dogs can apply information from previous experience to novel – or new – scents in order to apply an appropriate response.

Dr Anna Wilkinson from the School of Life Sciences at the University of Lincoln said: “As humans, we are very good at assigning different things to different categories; for example, we know something is a chair because there are identifiable aspects such as a flat space to sit on, or four legs. Categorising odours works the same way, and we were keen to discover whether dogs would be able to learn those skills.  

“This was an extremely hard task for the dogs as the odour stimuli varied in strength, so animals were never trained on exactly the same stimulus. As such, it is even more impressive that the experimental group dogs learned and retained the information.

“These findings add substantially to our understanding of how animals process olfactory information and suggest that use of this method may improve performance of working animals.”

The findings have implications in the field of working dog training as it implies that it may be possible to improve the way we train detection dogs.

Source:  University of Lincoln press release

How dogs can sniff out diabetes

A chemical found in our breath could provide a flag to warn of dangerously-low blood sugar levels in patients with type 1 diabetes, according to new research from the University of Cambridge. The finding, published in the journal Diabetes Care, could explain why some dogs can be trained to spot the warning signs in patients.

Claire Pesterfield, a paediatric diabetes specialist nurse at Addenbrooke’s Hospital, Cambridge University Hospitals NHS Foundation Trust has type 1 diabetes, which requires insulin injections to manage blood sugar levels. She also has a golden Labrador dog that has been trained by the charity Medical Detection Dogs to detect when her blood sugar levels are falling to potentially dangerous levels.

“Low blood sugar is an everyday threat to me and if it falls too low – which it can do quickly – it can be very dangerous,” says Claire. “Magic is incredible – he’s not just a wonderful companion, but he’s my ‘nose’ to warn me if I’m at risk of a hypo. If he smells a hypo coming, he’ll jump up and put his paws on my shoulders to let me know.”

Hypoglycaemia – low blood sugar – can cause problems such as shakiness, disorientation and fatigue; if the patient does not receive a sugar boost in time, it can cause seizures and lead to unconsciousness. In some people with diabetes, these episodes can occur suddenly with little warning.

Given the reports of dogs alerting owners to blood glucose changes, researchers at the Wellcome Trust-MRC Institute of Metabolic Science, University of Cambridge, believed that certain naturally-occurring chemicals in exhaled breath might change when glucose levels were low. In a preliminary study to test this hypothesis, the scientists gradually lowered blood sugar levels under controlled conditions in 8 women, all around their forties, and all with type 1 diabetes. They then used mass spectrometry – which look for chemical signatures – to detect the presence of these chemicals.

The researchers found that levels of the chemical isoprene rose significantly at hypoglycaemia – in some cases almost doubling. They believe that dogs may be sensitive to the presence of isoprene, and suggest that it may be possible to develop new detectors that can identify elevated levels of isoprene in patients at risk.

“Isoprene is one of the commonest natural chemicals that we find in human breath, but we know surprisingly little about where it comes from,” says Dr Mark Evans, Honorary Consultant Physician at Addenbrooke’s Hospital, University of Cambridge. “We suspect it’s a by-product of the production of cholesterol, but it isn’t clear why levels of the chemical rise when patients get very low blood sugar.

“Humans aren’t sensitive to the presence of isoprene, but dogs with their incredible sense of smell, find it easy to identify and can be trained to alert their owners about dangerously low blood sugar levels. It provides a ‘scent’ that could help us develop new tests for detecting hypoglycaemia and reducing the risk of potentially life-threatening complications for patients living with diabetes. It’s our vision that a new breath test could at least partly – but ideally completely – replace the current finger-prick test, which is inconvenient and painful for patients, and relatively expensive to administer.”

The research was funded by the National Institute for Health Research (NIHR) Cambridge Biomedical Research Centre with support from the Cambridge NIHR Wellcome Trust Clinical Research Facility.

Source:  University of Cambridge media release

The Florida sniffing dogs

The state of Florida is employing the use of some special Labradors in their fight for biosecurity.

Bear, Sierra and RJ are trained to follow the scent trails laid down by the invasive Giant African Land Snail.

Photo courtesy of Tampa Bay Times

Photo courtesy of Tampa Bay Times

The snail is a pest in the Miami area, where officials believe they have contained the spread of the pest.

The snails can grow as big as rats and they eat plants as well as stucco and plaster because they need lots of calcium to grow their shells. In large numbers, the snails have been known to cause extensive structural damage to buildings.  (And there’s lots of stucco in Florida!)

Photo by Andrew Derksen, Florida Cooperative Agriculture Pest Survey Program

Photo by Andrew Derksen, Florida Cooperative Agriculture Pest Survey Program

The snails can carry a parasite which is a human health risk because it can cause a form of meningitis but no cases have occurred so far in the United States.

The snails were introduced by a Santeria group which is a religion with a Caribbean and West African background.  The group would use the snails in religious ceremonies.

More fat and less protein for sniffing dogs

Sniffing dog checking luggage. (Credit: © Monika Wisniewska / Fotolia)

A detector dog checking luggage. (Credit: © Monika Wisniewska / Fotolia)

A study  funded with a $1 million grant from the U.S. Department of Justice, has found that detection dogs are more reliable detectors than previously thought.  The study has been conducted by Cornell’s College of Veterinary Medicine.

The study is the first to be conducted in the world’s only detection dog research facility designed in conjunction with a military dog trainer. The Alabama facility, which provides expert detection dogs to police and military forces, flushes out fumes between tests, ensuring a fresh field each time.

Researchers have found that the key to improving a dogs’ smelling skills through diet is achieved by limiting proteins and increasing fats.  Such a diet, the research team says, appears to help dogs return to lower body temperatures after exercise, which reduces panting and, thereby, improves sniffing.

‘Dogs tested in the new facility signaled with 90 percent and above accuracy. We also found we can push detection performance even further with the right kind of food.’ said Joseph Wakshlag, associate professor of clinical studies and chief of nutrition at Cornell’s College of Veterinary Medicine.

During an 18-month period, the research team rotated 17 trained dogs through three diets: a high-end performance diet, regular adult dog food, and regular adult dog food diluted with corn oil. Measuring how different diets affected each dog, they found that dogs eating the normal diet enhanced with corn oil returned to normal body temperatures most quickly after exercise and were better able to detect smokeless powder, ammonia nitrate and TNT.

‘Corn oil has lots of polyunsaturated fats, similar to what you’d find in a lot of nuts and common grocery store seed oils,’ said Wakshlag. ‘Past data from elsewhere suggest that these polyunsaturated fats might enhance the sense of smell, and it looks like that may be true for detection dogs. It could be that fat somehow improves nose-signaling structures or reduces body temperature or both. But lowering protein also played a part in improving olfaction.’

‘If you’re a dog, digesting protein raises body temperature, so the longer your body temperature is up, the longer you keep panting, and the harder it is to smell well,’ said Wakshlag.

Source:  Cornell University media release