If Dogs Can Smell Cancer, Why Don't They Screen People? (scientificamerican.com) 106
An anonymous reader shares an excerpt from a Scientific American report: Dogs can be trained to be cancer-sniffing wizards, using their sensitive noses to detect cancerous fumes wafting from diseased cells. This sniffing is noninvasive and could help diagnose countless people, which begs the question: If these pups are so olfactorily astute, why aren't they screening people for cancer right now? Here's the short answer: Dogs do well in engaging situations, such as helping law enforcement track scents or guiding search-and-rescue teams in disaster areas. But sniffing thousands of samples in which only a handful may be cancerous is challenging work with little positive reinforcement. Moreover, it takes time and energy to train these pups, who, despite extensive preparation, still might miss a diagnosis if they're having a bad day, experts told Live Science.
Uhh (Score:1)
If this is true, than something is being emanated into the air and can be detected by a man-made sensor.
Re:Uhh (Score:4, Interesting)
...something is being emanated into the air and can be detected by a man-made sensor.
The same can be said for drugs and we still use dogs for that.
Scent detectors (Score:5, Interesting)
The same can be said for drugs and we still use dogs for that.
That's because it is a hard problem to solve and dogs are exquisitely evolved to detect scents. Learning to replicate even a fraction of that functionality will take many years of hard work. And yes, top people are working on it [wikipedia.org].
Re: Scent detectors (Score:1, Insightful)
No, it's because dogs can key off of subtle, hard to detect signals from their handlers, and then "detect" the drugs and explosives which are carried by the people with the wrong skin color.
Cancer detection (Score:2)
No, it's because dogs can key off of subtle, hard to detect signals from their handlers, and then "detect" the drugs and explosives which are carried by the people with the wrong skin color.
Do you have a better scent detecting technology available? If not, shut up until you do. In any case the issues with drug sniffing dogs have nothing to do with cancer detection.
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The same can be said for drugs and we still use dogs for that.
But how much of that is just theater? Many "drug arrests" at airports are staged, with actors playing the criminals. The rationale is both training for the dogs and deterrence for would-be smugglers witnessing the "arrest".
A handheld scanner would take away the drama.
Re: (Score:2, Interesting)
Blind tests show that the dog mostly alerts on suspicion from the handler, rather than smelling anything.
And humans of course have almost as good of a nose as a dog. Dogs have a long snout because of the shape of their mouth. Dogs are good at tracking humans because they're close to the ground and don't have a social aversion to sniffing the ground. Humans do well at tracking if you get them to stick their face down there and do it.
Re:Uhh (Score:5, Insightful)
And humans of course have almost as good of a nose as a dog
Citation absolutely needed sir.
Re: (Score:2)
It's not the nose sensors, it's the number and percentage of neurons in the brain wired to olfactory pattern recognition.
Humans have good hardware for many senses, but our visual system is so good that we tend to favor it over the others and don't pay as much attention to the others because of it, which leads to a matter of practice. Dogs just rely on scent far more and get better at it, and are probably thus evolved to be fast learners with those neurons.
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"Olfaction, the act or process of smelling, is a dog's primary special sense. A dog's sense of smell is said to be a thousand times more sensitive than that of humans. In fact, a dog has more than 220 million olfactory receptors in its nose, while humans have only 5 million"
That's a pretty wide disparity. My money is on a dog being better at the smellings.
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My money
Exactly, when you don't read enough science news to know that there were important papers on this recently, then all you can do is make a guess. The most natural guess is whatever the old (known incorrect) belief was, in this case, that dogs are better at smelling than humans.
It goes right along with the misconception about the shape of the dog's mouth, that it would have a better sense of smell. Instead of, it has a long mouth so that it can bite at the legs of running animals, and that actually gets in th
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Instead of asking for a citation, you should just look it up and see if it is something with a bunch of citations.
Demanding citations from ignorance is absurd, and it isn't going to get you a specialized tutoring session. Look it up, say something more intelligent.
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You are just so wrong I don't know where to start. I've had hounds for close to two decades.
Have you ever guided a friend so you can grab a couple of french fries 3 blocks away in the curb? I had a beagle who would pull me on a different route to do just that. 3 french fries.
Have you ever smelled a rat in a tree 20 feet above you? I had a beagle who the first time he did that at 10pm at night I just thought was barking at the moon. Until I got the flashlight out and saw two beady eyes staring back at me I w
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He kept on going over to storm drains and I had no idea until somebody pointed out raccoons frequently live there.
Hmmm. Interesting. I thought it was just because my dog like the smell of stinky things (she really does). But perhaps this is the case.
I'll watch him follow the scent of a rabbit that he scared out of the bushes perfectly (he's old and has cataracts, so he doesn't see so well). This isn't one offs either. It's 4 or 5 times per walk.
My dog actually found a squirrel that was buried in snow looking for nuts a few weeks ago. She started digging like crazy in some snow and I thought she was just being her ridiculous self until I saw the squirrel. The areas we walk are full of homeless people and are traversed by hundreds of dogs, so she tends to get pretty distracted. When we used to live in a more r
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Re:Uhh (Score:5, Interesting)
Not quite. I have two SAR (Search and Rescue) dogs, and they are able to able to smell things we just plain can't. One dog can cover a 40 acre plot of land and find every human within about a half hour. He's found a dozen people (live and dead), and in many cases, places where ground-pounders and police already cleared. Our other dog is a sent-specific trailing dog and will follow the scent that a human leave along a trail for miles.
In all cases, during training and live searches, the handler has no idea where the subjects are. There is no indication that they can follow -- they lead us.
So -- read up. Your tests are bull shit.
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If this is true, than something is being emanated into the air and can be detected by a man-made sensor.
This was my immediate reaction too. Note that your point was answered only by conspiratorial flames about drug-snifffing dogs.
There is no incentive for dogs to falsely detect cancer, so if some of them can smell it, let's find out what they're specifically reacting to and design a chip for it.
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...your point was answered only by conspiratorial flames about drug-snifffing dogs.
"Conspiratorial flames"? I was just pointing out that drug-sniffing dogs are still in use. The point I was trying to make is that just because something is being emanated doesn't mean you can just grab a sensor off the shelf.
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If it's in the air, it should be possible to build a cancer-sniffing machine.
Of course it "should be possible." A lot of things "should be possible" that we're nowhere near accomplishing. We're pretty good with dogs.
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Pregnancy is cancer.
Nah... Fetuses are a parasites. They feed and grow off a host organism leaving the host organism weaker and less fit whilst carrying the parasite.
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Don't underestimate the power of deep-pocketed lobbyists. If they can bribe corporations into being people, then dogs can be corporations (or something like that).
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over the internet does anyone know they're actually corporations?
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How would detecting cancer have helped the owner to survive in the past?
Real answer (Score:1)
Drug sniffing dogs mostly respond to the officers' body language telling them to start barking to establish probable cause. Actually training them to respond to the smells is hard.
Cynical much? (Score:4, Insightful)
If dogs became mainstream at detecting cancers, there would be immediate palpable disruption to the present status quo. Schools that train doctors, radiologists and the whole associated ecosystem would be in peril.
Nice try but no. Under the best of circumstances dogs wouldn't be more than a cheap form of screening which would have to be confirmed by other more reliable methods of detection. Screening tests are useful but don't replace entire ecosystems of medicine. At most dogs can tell us that something is going on in the patient but they cannot provide much in the way of details.
Who in this industry, would support such a move? I do not see any.
My wife is a pathologist and she would happily support dogs being used to detect cancers if it were a practical and reliable approach. Nearly all doctors are more than happy to utilize any tool that will get better results for their patients. Your cynicism is misplaced.
Misplaced cynicism and anger (Score:2)
If cynicism is truly misplaced here, care to tell me why the fuck we haven't evolved in other areas of detection where we still use dogs?
Because we haven't got better technology yet. You seem to be under the delusion that scent detection is an easy thing to do. It isn't. Replicating even a fraction of a dog's nose is a problem as difficult as replicating human visual recognition. We've had some results but we're still not very good at it yet. There is lots of money to be made with artificial noses so I have little doubt it will get figured out eventually but until then we have to work with what we've got and what we've got are dogs.
Using "sniffing thousands of samples in which only a handful...is challenging work with little positive reinforcement" as an excuse to not use dogs to screen cancer seems pretty damn weak when that is essentially exactly what drug and bomb sniffing dogs are doing all day, every day.
We c
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We already have screening tests that aren't real accurate but serve to find people more likely to have some problem. Are there many lawsuits over mistakes in screening tests? My wife went through a screening test that showed (inaccurately) that she had Hepatitis C, and nobody ever mentioned a lawsuit.
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This argument is silly, the whole "Oooh, the cancer industry stops any fix for cancer, they could cure it but won't". You know why? Because the first Illuminati cancer industry exec who actually got cancer would immediately turn around and allow the secret fix.
Unless, of course, they're already secretly doing it, and magically keeping thousands of cancer cures secret...
WTF? (Score:3)
You think that, once a dog says that you have cancer, that's it? You don't need oncologists? You don't need radiologists? You don't need nurses?
The cancer dog sniffs you, wags his tail a certain way that means you have Leukemia, you take a Leukemia pill and that's it?
Have you had any experience with the medical profession at all?
Re: They [conveniently] miss the biggest reason... (Score:2)
Um, why would they be in peril? Their job is to cure cancer. If a new tool helps them find more cancers earlier, they'll have more cancers to cure (as opposed to cancers that aren't found until it's too late and kill people).
Why not build a machine that smells cancer? (Score:2)
Dogs can do amazing things, but they have approximately the same attention-span and cognitive function as a 2 year-old human--so maybe let's not trust cancer diagnosis to them.
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In order to make a machine to do the same thing, you would first have to know what it is you are looking for. And we don't know that. Sure, you can make a detector to smell a gas leak, we know what gas smells like. And you can make a detector to smell BAC, we know what that smells like. But we have no idea what the dogs are smelling when they smell cancer.
You can imitate a human eye pretty easily with a single light sensor and some processing. The human nose is not a single sensor (like an eye), it is
Re: They [conveniently] miss the biggest reason... (Score:2)
Schools that train doctors, radiologists and the whole associated ecosystem would be in peril.
Right, because once a dog 'detects' cancer in a person, there's no need for trained medical professionals (AKA doctors, radiologists, etc) - you just open a book that decodes the dog barks into a treatment plan then have Amazon drop-ship you a complete med kit to combat the cancer...
Detecting cancer =/= treating cancer.
A good screening test (Score:2)
Moreover, it takes time and energy to train these pups, who, despite extensive preparation, still might miss a diagnosis if they're having a bad day, experts told Live Science.
All screening tests have false positives and false negatives. That's why they are screening tests. A good screening test is cheap, fast, and has few (close to zero) false negatives and a modest number of false positives. Anyone with a positive test gets sent to follow up with more accurate and costly testing.
That said the article is right in that dogs really aren't sufficiently reliable. Same problems exist with search and rescue dogs. If it isn't fun for them even the best dogs get bored and stop coop
Bees (Score:5, Interesting)
Bees are just as good as dogs at sniffing things, including drugs and explosives.
You train the hive ONCE, and they train each other after that.
Unlike dogs, they have much longer working rules. They don't need as much rest or reward.
http://www.seattlepi.com/news/... [seattlepi.com]
http://mentalfloss.com/article... [mentalfloss.com]
You: Dr, I have a history of cancer in my family (Score:5, Funny)
vs
Dr: Please step into this room FULL OF BEES.
Re: (Score:2)
It'd certainly cut down on the number of hypochondriacs wasting doctors' time...
Bees (Score:2)
Basically, http://www.youtube.com/watch?v... [youtube.com] ... :P
More Important Question... (Score:2)
Re:More Important Question... (Score:4, Interesting)
Actually no. Skin and lung/throat/mouth cancers are perhaps the easiest to smell, but dogs have been shown capable of relyably detecting a wide range of other cancers as well, along with a wide range of other diseases with no obvious surface symptoms. Presumably anything that alters your body's chemistry has a fair chance of introducing telltale molecules into your sweat, breath, urine, etc. And cancer uses metabolic pathways not normally used by healthy cells (most produce energy in the cytoplasm rather than the mitochondria), which probably means unusual waste products dumped into the blood stream.
The post answers it's own question.. (Score:2)
"But sniffing thousands of samples in which only a handful may be cancerous is challenging work with little positive reinforcement. Moreover, it takes time and energy to train these pups, who, despite extensive preparation, still might miss a diagnosis if they're having a bad day, experts told Live Science."
Next mystery: why do I get wet every time I have a shower?
There is no begging (Score:5, Informative)
It raises the question. It does not beg the question.
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maybe it was a play on words, dogs, begging... c'mon expound your mind! It's not that hard to see outside the box. The forest with trees and all that.
"Hello, ladies..." (Score:5, Informative)
If dogs are cancer-smelling machines, then every single dog in my local dog park must have cancer of the ass.
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Or maybe my dog's just providing free ass cancer-screening services to every dog in the dog park. Yeah, I like that idea better.
What is the point of this post? (Score:2)
The summary describes the question, then provides the answer!
False positives (Score:2)
Because you have the potential for a ton of false positives that cause mental anguish of "do I have cancer" and related testing to rule out an actual positive.
The role the dog (or bees, or what have you) play currently is probably the right one, used only when needed and validated with other methods with higher precision.
Invert the logic - save the day (Score:2)
citation: "But sniffing thousands of samples in which only a handful may be cancerous is challenging work with little positive reinforcement."
changed: "But sniffing thousands of samples in which mostly all are not cancerous is -still- challenging work with much positive reinforcement."
-> Train the dogs to _not_ react on cancerous people.
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Or throw in a patient with known cancer now and then, to raise the positive rate.
It doesn't "beg the question." (Score:3, Insightful)
It doesn't "beg the question." Check your dictionary (despite the overwhelmingly incorrect use of that phrase.)
Re: (Score:1)
Let's see...that's the name of that book which included a theme about how modifying language modifies thinking? Oh, yes, I remember several books about that. And of course we are experiencing that action and effect in our political and social discourse these days too. So what does linguistic and cognitive corruption matter ...
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Let's see...that's the name of that book which included a theme about how modifying language modifies thinking? Oh, yes, I remember several books about that. And of course we are experiencing that action and effect in our political and social discourse these days too. So what does linguistic and cognitive corruption matter ...
"What's" not "That's."
Dogs need positive reinforcement. (Score:2)
When sniffing for cancer, you can't exactly say "Good boy. This poor man has cancer, here's a treat!". You can't base a diagnosis on the reaction of dog, and certainly not in front of the patient. The cancer would h
Cat scan (Score:2)
We don't have dog cancer tests yet, but we do have CAT scans!