Substance Detection Golden Retrievers: Illness
Dogs are used to warn of epileptic seizures, low
blood sugar, high blood pressure, migraine headaches, and heart attacks.
Research in this area is based on the theory that disease causes
subtle chemical changes in the body or alterations in metabolism, which in turn
releases a different smell, or chemical marker.
“This isn’t anything
magic,” says Dr. Larry Myers, associate professor at the Auburn University
College of Veterinary Medicine in Auburn, Ala., who has personally tested the
olfactory capabilities of more than 4,000 dogs over the last two decades.
“Physicians have always used their own senses to determine the presence or
absence of disease.” In fact, diabetes was once diagnosed by smelling or tasting a patient’s urine.
Some types of infections present in burn victims can also be
detected by the smell of a patient’s skin, and we all know that bad breath can often
be a sign of periodontal
"It's [epilepsy] a chronic condition and [an attack] is literally an
electric storm in the brain that can change behaviours," explained Dr
Blanca Vasquez, director of clinical research at New York University's
Comprehensive Epilepsy Centre. While seizures can vary greatly in their
intensity and outward manifestations, many are preceded by sensations
known as an aura, she said.
Not known what dogs are responding to
Even from far across a room, seizure-alert dogs seem to be able to pick
up on extremely subtle physiological changes - minute alterations in
odour or movement - that may begin anywhere from 45 to five or 10
minutes before an actual attack. "More research needs to be done,"
Arnold said. "We don't exactly know right now what the dogs are
But their ability to sense these changes for their owners can be
invaluable, since early warning of a seizure's onset helps people with
epilepsy find a safe environment or take precautionary measures. The
Labradors and retrievers trained by the experts at Alpharetta, Ga.-based
Canine Assistants begin their 18 months of instruction at just 2 days of
age, learning over 90 standard commands. More mysteriously, some
protective measures seem to come to the dogs by instinct, Arnold said.
For example, when sensing an oncoming seizure, "they tend to want their
person to lie on the ground," she said.
As any person with epilepsy will tell you, that's about the most
sensible action an individual can take before a seizure, since falling
is the leading cause of serious injury during an attack.
Seems to know instinctively
"It's fascinating - dogs who have never seen anyone have a seizure will
tug at their person's sleeve, they want you on the ground," Arnold said.
"How do they have that instinct that lying on the ground is safer? We
have no idea."
Epilepsy Foundation notes that interest in seizure dogs began in the
mid-1980's, when a woman with epilepsy who was taking part in a Washington state
prison project involving dogs discovered that one of the dogs seemed to know
when she was going to have a seizure. The Lifetime TV drama, "Within These
Walls," is based in part on this experience.Now the term is used to cover activities such as: dogs trained to bark or
otherwise alert families when a child has a seizure while playing outside or in
another room or to lie next to a person having a seizure to prevent injury.
Although these dogs are responding no differently than other assistance dogs,
the issue of seizure prediction is a cloudy one as most report that dogs with
this ability have only developed it over time, the talent actually discovered
accidentally. In 1998, Roger Reep, Ph.D., an associate professor in the
department of physiological sciences at the University of Florida, surveyed 77
people between the ages of 30 and 60 who had epilepsy. The survey asked about
their quality of life, medical status, attitudes toward pets, ownership of dogs,
and their pets' behavior prior to and during a seizure. Only 3 out of the 31
felt that their dogs seemed to know when they were going to have a seizure (10
percent). Another 28 percent said their dogs stayed with them when they had a
seizure. According to his research, the behavior seems to occur spontaneously
and may occur in as many as one in ten situations when the owner is having at
least one seizure per month. Dr. Reep concluded that reports of seizure-alerting
behavior in dogs should be viewed as credible, but with caution.
Dr. Stephen W. Brown, a British neuropsychiatrist and epilepsy specialist, and
Val Strong, a behavioral scientist and animal trainer, reported in 1999 in the
European Journal of Epilepsy Seizure that, working with people with epilepsy and
dogs together, they were able to train some of the dogs to warn of seizures. The
training was based on reward-based operant conditioning. In effect, the dogs got
a reward every time their owners had seizures. "After a while those dogs that
are going to be able to act as seizure-assistance dogs start to alert and expect
their reward before the person's had the seizure," Dr. Brown said. The dogs he
was training were sometimes able to give warning as much as 15 to 45 minutes
before the actual seizure occurred. The way the dogs behaved took different
forms, from pawing in a special way to simply approaching the person and
barking. Dr. Brown also found that, following this type of training, the actual
number of seizures decreased.
In the Seizure March 2003 article,
Seizure-alert dogs: a review and preliminary study(Dalziel; Uthman;
Mcgorray; and, Reep, Department of Neuroscience, College of Medicine, University
of Florida), the findings suggested that some dogs do have the innate ability to
alert and/or respond to seizures. The research additionally suggested a trend in
the type of seizure/auras dog may be alerting to. However, the success of these
dogs depended primarily on the handler's awareness and response to the dog's
alerting behavior. The authors did see the need for further research to aid in
the selection of those who may benefit from seizure-assist dogs, for
identification and further training of these dogs and possibly the development
of seizure-alerting devices.
A more current review of the literature can be seen in Drs. Doherty and
Haltiner's 2007 Neurology article, Wag the
dog: Skepticism on seizure alert canines. Reports of dogs that can predict their owners' epilepsy seizures have
been anecdotal and not objectively confirmed by doctors and researchers. The article
also looks at the controversy regarding
NonEpileptic Seizures (PNES), with dogs thought to be responding more to
psychological seizures, rather than epilepsy seizures. PNES may look like
epileptic seizures, but are not caused by abnormal brain electrical discharges.
Instead, they are a manifestation of psychological distress. By definition, PNES
are a physical manifestation of a psychological disturbance and are a type of
Somatoform Disorder called a conversion disorder.
Dr. Michael J. Doherty, MD, of the Swedish Epilepsy Center, and a member of the
American Academy of Neurology, said the findings raise several questions that
need to be further investigated. "If dogs can predict psychological seizures,
could the seizures be a conditioned response to stereotypical dog behaviors?
Does having a seizure alert dog lead people to have psychological seizures more
or less often? Given the cost of training seizure alert dogs, should people
requesting one be screened for psychological seizures?"
Pseudoseizure Dogs, a 2007 article In the American Academy of Neurology
from Dr. Gregory L. Krauss, MD, of Johns Hopkins University School of Medicine,
concludes that those with psychogenic seizures need psychiatric evaluation and
appropriate treatment, not a specially trained dog for epileptic seizures. "This
is important because the treatment is very different for a person with epilepsy
and one with psychological seizures, which stem from emotional difficulties,"
said Krauss. "Epilepsy drugs are not effective for psychological seizures, and
they often have side effects. And with proper treatment and counseling,
psychological seizures can often be eliminated."
Krauss said it's possible that people with psychological seizures may seek out
service animals for support. He noted that some people with epileptic seizures
may benefit from seizure response dogs. "Seizure response dogs can help people
during seizures and stay by them when they are unconscious and provide
companionship that aids them in dealing with a chronic disorder," Krauss said.
"People with nonepileptic seizures require psychiatric evaluation and behavior
therapy. This study demonstrates the importance of establishing an accurate
diagnosis of epilepsy before obtaining a seizure response dog."
Diabetes: Medical Alert Dogs Dogs for Diabetics is an
innovative non-profit organization that provides quality medical alert
assistance dogs to youth and adults who are insulin-dependent type 1 diabetics
through a program of training, placement, and follow-up services. Dogs4Diabetics
dogs have been specifically trained to identify, and more importantly, act upon
the subtle scent changes that hypoglycemia (low blood glucose) creates in body
chemistry, changes undetectable to their human companions.
Low blood sugar initially causes stomach cramps, disorientation and a sweat, but
later the body becomes accustomed to these lows and stops sending out danger
signals. That's where these specialized dogs come in, earning the right to sleep
in the room with its owner. While everyone is certainly different, they say 3
a.m. seems to be the favored time for a crash. In a
November 5, 2006 San Francisco Gate article, written by Sam Whiting, we
learn about such times and how these canines step up to the plate.
"My blood sugar suddenly goes low and I don't wake up. I don't feel
anything and suddenly there will be a 130-pound golden retriever jumping
on me," says Devin Grayson, who is 36, lives in Oakland and has been
Type 1 for half her life. Once rousted she checks her blood sugar to
make sure Cody is right. A diabetes dog does not get its owner out of a
finger prick to draw blood and test. Grayson goes low at night three
times a week, and Cody hasn't been wrong in six months. He's a more
accurate predictor than the meter, because his nose picks up a trend
downward in blood sugar that the meter won't. If Grayson were to become
non-responsive, Cody has been taught to find help and lead it back,
which Grayson describes as a "Timmy's-in-the-well episode.''
All the Lassies lodge with foster families while they are being trained.
The curriculum is a simple reward system. The hypoglycemic scent is
captured on the shirt of a hypoglycemic diabetic and hidden among
trainers. Detect the smell on the right person and the dog gets a
reward. The humans take more training than the dogs. "We start with
Puppy 101," Ruefenacht says. Applicants must have control over their
diabetes and fill out a questionnaire available at the Web site
dogs4diabetes.com. They are looking for a perfect match between woman
and best friend,
Cody continues sharpening his skills while Devin works as the
Director of Communications for Dogs4Diabetics.
At Heaven Scent Paws, their
trained Diabetic Alert Dogs detect and alert their diabetic partner and support
team (parents, spouse, friend, etc) to both low blood sugar (hypoglycemia) &
high blood sugar (hyperglycemia).
Canine cancer detection is an
approach to cancer screening that relies upon the olfactory ability of dogs to
detect very low concentrations of the alkanes and aromatic compounds generated
by tumors. Although the first suggestion of this approach in a medical journal
dates back to 1989, there was little further investigation for the next decade.
However, two studies (one published in 2004 and one in 2006) had promising
results, with the 2006 report claiming a 99 percent accuracy in detecting lung
cancer, although both studies were preliminary and involved small numbers of
In 1994, Dr. Armand Cognetta, a Tallahassee
dermatologist and retired Tallahassee police officer Duane Pickel, got together to see if
dogs could be trained to detect cancer. As we have several successful Goldens in arson and
drug detection, it seemed possible to train for cancer detection. To a dog's powerful
nose, it appears that cancer cells have an odor that is different from that of healthy
cells. Golden Retriever owner and trainer Glenda Manucy and her dog, Colabaugh's Morninglo
Breeze UDX, MH, joined the team in June 1994. It only took Breeze a month to be able to do
test searches. Here she is sniffing at every Band-Aid, searching for the one with cancer
cells. Breeze correctly identified the one with the cancer cells and then alerted this by
sitting. If asked to "Show me," she would tap the Band-Aid with her paw.
A lung specialist, Fr Clinton
"Bud" Bailey joined the project, interested in learning whether a similar
procedure could be used for the early detection of lung cancer. In December 1994, a
specially made rack containing sample test tubes was provided to teach Breeze to detect
lung cancer cells. Using this rack, a patient would breathe into one of the tubes, which
was then sealed, and racked with the others. As she walked along one side of the rack, the
tubes were opened. That allowed Breeze to smell the air coming from the tube. Just like
the skin cancer tests, the signal of alerting to a different smell was to sit in front of
the suspect tube.
More controlled research needs to be done,
and the next step may also be to try and determine just what it is that these dogs are
calling cancer. Pickel and Manucy would like to continue to be involved in any new
research. They would also like to be able to train Physician Assisting Canines (PACS) for
other doctors to continue this work on skin and lung cancer detection. This kind of
detection, of course, would not replace the diagnosis needing to be done by a physician.
Yet, this method may be able to get people to their doctor before they have outward
symptoms. And, then lives could be saved.
More recent small-scale studies of dogs’ ability to detect the
chemical markers of cancer, specifically melanoma, have shown very promising results
with a dog's ability to differentiate between healthy skin cells and
cancerous ones. Work is under way to determine whether dogs can accurately diagnose
Biodiagnostics is the diagnosis of human diseases with the help of
animals such as sniffer dogs. Understanding how dogs detect cancer by smell may soon
help scientists develop new technology to help detect melanoma and other cancers
at early stages. Though scientists do not know yet whether
dogs detect enzymes, proteins, antibodies, or other molecules of melanomas,
further research with canines may allow them to develop new medical equipment.
There are two proposed benefits, assuming that further studies corroborate the
initial results. Some researchers believe that dogs will become integrated
directly into patient care, akin to their use in detecting bombs, drugs, and
missing people. Others recommend that the skill of dogs in detecting cancer
would be more appropriately confined to labs, where gas chromatographs could be
used to isolate which specific compounds the dogs identified.
TaleTell: Your own Stories of Disease Detection Goldens Meet some wonderful 4-footed detectors.
And, if you have a story to tell of a Golden alerting to: an approaching seizure,
low blood sugar, migraine headache, rise in blood pressure, presence of cancer,
etc., just send it along with photos to: back