*An Introduction To The Horse Nervous System

The nervous system is complicated because it is in charge of so many things. Basically there are 3 sections and 2 operating systems. There is the brain stem which houses the ancient portion that connects the brain to the body through the cranial and spinal nerves. Here the basics are covered such as breathing and digestion movements. On top of this is ancient center is the cortex which has a more developed portion of the brain and does some of the thinking. Here is where we feel hunger, danger and the need to reproduce. Over this is a very thin layer called the neocortex which houses all of the memories of our life. All 3 sections connect with an uncountable number of nerve fibers interacting using chemicals called neurotransmitters. The 2 operating systems are the parasympathetic and the sympathetic which control the non-thinking parts (heart beat, digestive contractions, etc) or the voluntary parts (I’m hungry and I’m going eat).

Through shared connections, all sections of the brain use patterns to cause actions. Hunger may come from either the action of a hormone secreted by various factors such as an empty stomach or from a smell (fresh muffins from the oven) or from a visual (see a commercial on TV or see the barn worker arrive = feeding time). Seeing some foods may cause us not to eat it because last time it was eaten there was a violent stomach reaction (memory of a bad event).

There are groups of cells identified in the brain of all animals that are called islands and are named. Of importance to horses are the amygdala which stores emotions including the fight or flight survival reaction. Directly connected to this is the motor cortex where movement starts. This connection is responsible for the explosive reaction a horse may have to a stimulus such as a surprise movement outside the window. Only in a long moment does the horse understand the movement and no longer moves as his safety is assured, but you might be injured from his reaction. Other times they connect a person (trainer, vet) with an unwelcome emotion in the amygdala and running or rearing occurs. What needs to be changed then is the stimulus and the reaction to that stimulus (training).

The number of problems in the nervous system of horses are limited to central (brain) and peripheral (nerves). Central diseases include rabies and other viral infections, meningitis from a bacterial infection and dummy foal syndrome from lack of oxygen at birth. Also cataplexy / narcolepsy where the horse suddenly collapses apparently asleep and Cushing’s disease and other neurodegenerative syndromes where the hypothalamus of the brain no longer communicates with the pituitary.

Peripheral nerve diseases (neuropathies) include direct trauma to any nerve (Sweeney and other muscle atrophies due to nerve loss), secondary trauma (wobblers, roaring) and inflammatory diseases (head shakers, shivers).

New discoveries in the human brain could also be thought to occur in horses. It is known that there is a unique lymph system of the brain called the glymph system. This fluid bathes the brain after it shrinks up to 40% during deep sleep (delta wave) cleansing the brain of waste. Cognitive dysfunction in humans has been associated with inflammation due to diet and dementia in humans is now being called diabetes type 3. Something similar in horses is not known but could this be happening to horses with metabolic syndrome and insulin resistance (diabetes)? No one is testing for this in horses.

New nerve diseases in horses since I went to vet school include ALS (Lou Gehrig’s Disease) and head shaker syndrome. Other nerve diseases that have increased are cataplexy and shivers. I’ll look at all of these in the included topics.

Base Modifiers – The Silver Gene

SummaryArticleVideosRelated Material The silver gene (Z) is a dilution of the black base coat with or without the Agouti gene (bay). It has no effect on the red base coat. Horses with one or both Z genes will have a dilution to their coat color and therefore it is an...

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Hyperkalemic Periodic Paralysis (HYPP)

SummaryArticleVideosRelated Material Welcome to this topic page.  Right now I have not written an article and summary but be sure to check for images in the gallery. As time moves on I am adding summaries and articles, videos and podcasts so eventually there will be...

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Polysaccharide Storage Myopathy (PSSM)

SummaryArticleVideosRelated Material Welcome to this topic page.  Right now I have not written an article and summary but be sure to check for images in the gallery. As time moves on I am adding summaries and articles, videos and podcasts so eventually there will be...

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Sinus Infections

[x_alert type=“info” close=”false” heading=”Overview”]The epiglottis is a tissue that separates the esophagus from the trachea and it’s primary purpose is to keep food and other solid material from entering the lungs.[/x_alert]

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Pharyngitis

[x_alert type=“info” close=”false” heading=”Overview”]The epiglottis is a tissue that separates the esophagus from the trachea and it’s primary purpose is to keep food and other solid material from entering the lungs.[/x_alert]

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*An Introduction To The Horse Urinary System

Blood circulates throughout the body delivering all the materials needed to stay alive but it also acts as a system to recycle materials, return gasses and eliminate waste. In this sense it acts like the post office, the package delivery service, the messenger service...

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Unknown Neoplastic Lesions

Equine Sarcoid is a benign tumor of the skin of the horse that is very common, usually limiting itself to above the knee and forward of the girth.

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Fibrotic Myopathy

SummaryArticleVideosRelated Material Welcome to this topic page.  Right now I have not written an article and summary but be sure to check for images in the gallery. As time moves on I am adding summaries and articles, videos and podcasts so eventually there will be...

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Caudal Heel Pain Videos

These are videos about caudal heel pain which includes navicular disease, sole bruising, long toe-low heel conformation and others. Return to caudal heel pain Navicular disease (caudal heel pain) – Part 1 Navicular disease (caudal heel pain) – Part 2...

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The Curly Hair Coat

The breed Bashkir Curly has a hair that maintains a curl throughout the year. The curl can range from no curl to minimal to full curl but it is unique to this breed.

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Anhidrosis (Non-sweating horses)

No one has determined why some horses in the same environment stop sweating while others do sweat but we know that every horse is different with different responses to triggers. And no one (to my knowledge) has determined the mechanism behind anhydrosis.
Accidentally we have found a cure that seems to work in every horse we try it with and we need your help to give us more examples of this treatment’s success.

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Vesicular Stomatitis

SummaryArticleVideosRelated Material Welcome to this topic page.  Right now I have not written an article and summary but be sure to check for images in the gallery. As time moves on I am adding summaries and articles, videos and podcasts so eventually there will be...

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Tetanus

SummaryArticleVideosRelated Material Welcome to this topic page.  Right now I have not written an article and summary but be sure to check for images in the gallery. As time moves on I am adding summaries and articles, videos and podcasts so eventually there will be...

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Aging By Teeth – View Open Mouth

These images include all the ages from 2 years to 30+ years showing just the view from the opened mouth onto the occlusal surface of the incisors. This helps to compare and to observe the changes over time on one individual view.

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Aging By Teeth – View Straight On

These images include all the ages from 2 years to 30+ years showing just the view from straight on the closed incisors. This helps to compare and to observe the changes over time on one individual view.

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Aging By Teeth – View Right Side

These images include all the ages from 2 years to 30+ years showing just the right side. This helps to compare and to observe the changes over time on one individual view.

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Aging By Teeth – View Left Side

These images include all the ages from 2 years to 30+ years showing just the left side. This helps to compare and to observe the changes over time on one individual view.

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Aging By Teeth – 02 – 5 years (Young Horses)

Young horses range in age from birth to 5 years. These images are by year 2 through 5. Each show the left side, the right side, the straight on and the open mouth / occlusal surface of the lower incisors. Comparison can be made for individual variations within each age group.

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Aging By Teeth – 06 – 12 years (Young Adult Horses)

Young adult horses range in age from 6 to 12 years. These images are by year 6 through 12. Each show the left side, the right side, the straight on and the open mouth / occlusal surface of the lower incisors. Comparison can be made for individual variations within each age group.

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Aging By Teeth – 13 – 18 years (Adult Horses)

Young adult horses range in age from 13 to 18 years. These images are by year 13 through 18. Each show the left side, the right side, the straight on and the open mouth / occlusal surface of the lower incisors. Comparison can be made for individual variations within each age group.

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Aging By Teeth – 19 – 24 years (Early Senior Horses)

Young adult horses range in age from 19 to 24 years. These images are by year 19 through 24. Each show the left side, the right side, the straight on and the open mouth / occlusal surface of the lower incisors. Comparison can be made for individual variations within each age group.

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Aging By Teeth – 25 – 30 plus years (Senior Horses)

Young adult horses range in age from 25 years and older. These images are by year 25 through 30+. Each show the left side, the right side, the straight on and the open mouth / occlusal surface of the lower incisors. Comparison can be made for individual variations within each age group.

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Dental Care

Horse’s teeth erupt throughout their lives with constant wear occurring from teeth grinding against opposing teeth and continual stropping by the tongue. This wear is uneven and creates razor sharp edges that cause discomfort as those edges ulcerate the cheek and their tongue. So if eruption and wear is continuous throughout the life of the horse and the result is pain within the mouth, AND the removal of the sharp points (floating) is easily done, WHY DO SO MANY HORSE OWNERS AVOID THIS IMPORTANT ASPECT OF HORSEMANSHIP?

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Asses, Mules And Zebras

SummaryArticleVideosRelated Material Welcome to this topic page.  Right now I have not written an article and summary but be sure to check for images in the gallery. As time moves on I am adding summaries and articles, videos and podcasts so eventually there will be...

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Guttural Pouches

SummaryArticleVideosRelated Material Welcome to this topic page.  Right now I have not written an article and summary but be sure to check for images in the gallery. As time moves on I am adding summaries and articles, videos and podcasts so eventually there will be...

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Mustaches

SummaryArticleVideosRelated Material Some horses have a natural mustache as seen here.  I have seen a bunch in my years with horses but I have never heard any meaning attached to their presence other than most people think they are “cute.” Related material...

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