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Tuesday, March 12, 2013

Lost Dogs Really Don't Recognize Their Humans

When encountering a stray dog that you want to contain, even when it's your own dog, the advice is always to avoid calling out to it, making eye contact, etc. Dog owners often have a pretty hard time grasping the idea that their own dog would not come to them or even recognize them. Consider this excerpt, paraphrased from the Loudoun Times on 1/6/11

“She didn’t recognize me or my voice,” Reilly-Greiner said. “The wind was blowing against me, so she couldn’t pick up my scent, either. There was no recognition. I was a stranger to her."

While patrolling the area 32 days after her dog went missing, Carrie Reilly-Greiner spotted Sage feeding on a deer carcass. Despite gentle calls to her dog, Sage did not respond to her owner. Hours later, after the dog was humanely trapped and reunited with her, Carrie made this observation:

"Once I was in front of her, a very strange thing happened. You see, dogs have serotonin in their brains, which makes them act domesticated. And when that serotonin dissipates, as it does very rapidly when a domesticated dog is out in the wild, they revert to survival mode. Once I was reunited with her, I could literally see the serotonin kicking back in. She began to lick me and cry and wag her tail. It was quite a remarkable moment.”

What is serotonin?
Serotonin is a hormone found naturally in the body which acts as a messenger between nerve cells. It regulates a number of key physiological processes, including short term memory, sensory perception, sleep, mood and depression.

What are the effects of depleted levels of serotonin?
When levels of this crucial hormone are depleted, the body's natural rhythms are disturbed. Low levels of serotonin can lead to depression, while normal levels lead to a state of calm. Chronic serotonin depletion significantly impairs short term memory, but not long term memory.

What causes depletion of serotonin levels?
There are several causes for reduced levels of serotonin, many of which are environmental factors that people face on an everyday basis. Since dogs also have serotonin and are similarly affected, consider each factor listed with a dog on its own in mind.

Poor Diet
Our bodies produce serotonin while digesting foods which are healthy and contain the amino acid L-Tryptophan. Serotonin deficiencies may cause a chemical imbalance which can be the result of poor nutrition. Serotonin levels can be affected by an unbalanced diet, as an adequate protein supply plus specific vitamins and minerals are necessary to build neurotransmitters. Protein contains tryptophan, an amino acid that turns to serotonin in the brain. Some specific vitamins and minerals are known as cofactors, and when too few cofactors are present in the body due to poor nutrition and low protein intake, a neurotransmitter imbalance arises.

Stress
Whether brought about by everyday life as a dog on the run or by a significant traumatic event, prolonged or intense stress has been found to cause changes in the brain's chemistry, including the depletion of serotonin. A1989 study revealed that chronic stress caused by ongoing problems or a specific stressful incident likely contributed to neurochemical changes in participants, leading to episodes of depression.

Low levels of serotonin are directly related to stress, especially long term stress. We are becoming a “serotonin deficient” society due to chronic stress, lack of exercise and a proper well-balanced diet, and poor sleeping habits. Managing stress through support systems, exercise, relaxation techniques and adequate rest will also replenish serotonin levels. These strategies will further promote the refueling of serotonin.

Lack of Sleep
Lack of sleep negatively affects our brains' neuronal signaling, including how it responds to serotonin. Sleep deprivation has been shown to desensitize serotonin pathways, meaning that consistent lack of sleep has a negative impact on our brain’s response to serotonin in general. This means that consistent healthy sleeping patterns are key to maintaining healthy serotonin signaling in our brains and likely our bodies in general.

Chemical Substances
Certain substances in our environment can be to blame for cases of depleted serotonin levels in the brain. Exposure to harsh chemicals such as pesticides and heavy metals can lead to permanent damage to the nerve cells responsible for producing serotonin.

Lack of Sunlight
Increasing research has revealed a link between lack of sunlight and depleted serotonin levels. When the body's internal clock does not receive signals from the sunlight to release certain energetic hormones such as serotonin, levels of this nerve transmitter are lowered. A study conducted at the University of Toronto shows that sunlight controls serotonin transporters, which are proteins that prevent nerves from receiving serotonin. The study found that higher levels of serotonin transporters were found in the brain during darker autumn and winter months, leading to depleted serotonin levels.

Lack of Exercise
Exercise boosts blood and brain serotonin levels immediately, and it helps regenerate neurons. Increased neuron production gives our brains better ability to utilize the serotonin boosts. Exercise also allows our brains cells to function better by making them more flexible, leading to better responses to all neurotransmitters, including serotonin.

Genetics
For those (people) found to have inherited a genetic defect in the brain's serotonin receptors, it is difficult for these receptors to absorb the brain's circulating serotonin. This defect makes serotonin receptor sites shorter than they normally would be, hindering their ability to both receive and release serotonin in the brain.

Impacts on serotonin levels in stray dogs
  • Poor diet and stress are the most significant serotonin-related risks for dogs on their own
  • Exercise and sunlight are probably not risks for most stray dogs
  • Since the sleep habits of stray dogs v homed dogs is an unknown, it is harder to discern its effect on serotonin levels in dogs on their own
  • Exposure to chemicals such as pesticides is likely not a high risk for most at large dogs

Impacts of depleted serotonin levels in stray dogs
  • Stress typically contributes to at large dogs avoiding help offered by humans.
  • Dogs with bonded owners often fail to recognize their own human family members due in part to stress and short term memory loss as it relates to compromised serotonin levels.

3 comments:

Jastatu said...

This is fantastic info. As co-founder of the Nova Scotia Lost Dog Network (ns.lostdognetwork.com) I've tried to explain to many a dog owner that their dog may not come to them. Having yet another way of explaining it may help owners to learn the proper approach. Thank you so much for a very informative blog.

Bryan Johnson said...

I definitely enjoying every little bit of it and I have you bookmarked to check out new stuff you post.

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Unknown said...

fantastic work, i really appreciate it. Lost and found