Introduction
Back in 1988, when I graduated from Douglass College (Rutgers University) with a B.A. in Neurophysiology and Behavior, we had ONE brain physiology textbook!
This was a pretty big volume, but had many blank pages with just a brief note that not much was known about this-or-that part of the human (or animal) brain.
A good great deal has changed since then!
Pet owners can even consult with specialists in Veterinary Neurology when their general practicioners confront brain conditions that resist definition and/or treatment.
Although we still have practical limitations (new conditions are being described all the time), there is a lot more that we can do for our pets when they suffer from injuries, organ dysfunction and autoimmune problems that adversely affect brain function.
Neurology (Brain Stuff) Library
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Myositis
Lumbar Disc Rupture
Spinal Cord Embolism
Seizures
Some seizure disorders have a cause, such as pre-existing illness (lissencephaly, diabetes, kidney or liver failure, hypoglycemia), toxins, tumors or physical injury (like being hit by a car) that has damaged the brain.
Some seizure disorders are what we call Idiopathic (sickness without a known cause). This would include developmental defects, and many conditions we do not yet know how to identify using current medical technology.
Sometimes a dog will have one seizure, and never another...these seizures are very hard to blame on any one thing or another.
Dogs that have regular seizures that are not linked with any other illnesses are said to be Epileptic. Most dogs with simple epilepsy can be well treated with drugs.
Seizures can be brief or prolonged. They can be mild in their appearance or physically violent. The more vigorous and the more prolonged a seizure is, the more dangerous it is to the brain. Dogs that do not loose consciousness, and even exhibit strange or out-of-character behaviors, fall into the class of Complex Partial Seizures...seizures confined to a very small part of the brain. Grand Mal seizures are the typical thrashing, drooling events that most people are familiar with through the media. There can be a whole range of variations in between.
An older pet experiencing a violent seizure, or repeated seizures, is more likely to be harboring a serious health problem, such as cancer, brain hemorrhage, or organ failure.
Diagnosis can be as simple as running some blood tests, or as complicated as undergoing an MRI to find a tumor or other brain-threatening condition. Deciding what tests to run, or whether to seek the opinion of a Veterinary Neurologist are very individual decisions that depend partly on your pet's ability to undergo the testing and partly on your family's finances.
If a root cause of the problem can be found, then addressing it can stop the seizures from repeating in the future, but some conditions that affect the brain can also leave permenant damage.
If no root cause of repeating seizures is found (like Lyme Disease, Toxoplasmosis, tumor, etc), then medications are started to prevent new ones from developing. Once a pet starts such a therapy, it should not be stopped without medical assistance...skipping doses can bring on worse seizure activity. Blood testing is periodically used to make sure that your pet is getting the proper amount of medication. Sometimes seizures "break through" medical therapy, and other drugs can be added to help control this as well.
Certain medicines are known to bring on seizures (by changing brain activity)...among these are antihistamines (like diphenhydramine, hydroxyzine, chlorpheniramine, etc.), tranquillizers (acepromazine and its relatives), and antianxiety drugs (clomipramine for sure, and others). Never use medicines that have not been approved by your dog's veterinarian!
Once a pet has been determined to need medication, it is not safe to assume that he will ever be able to do without it in the future.
Cervical Neck Pain/Wobbler's Syndrome
Cervical neck symptoms in dogs are every bit as awful as lower back problems are in people...a dog's neck bones and back muscles work very hard to hold the head up all day. It can take quite a long time for a pet to feel back-to-normal; a month at the minimum is not out of the question.
Each pet is an individual, but even a "simple" strain or nerve pinch can lead to an extreme experience of pain. Affected dogs prefer to not move, hold the head forward or slightly down, and are distressed when they anticipate pain...i.e., they tense up even before anyone touches them or picks them up.
Morning is often worse, especially for those pets that don't move a lot overnight during sleep, sleep on drafty flooring, or are overweight. Making sure that your pet has a most comfortable surface to lie on in a room that is not too cool may help, but let him rise at his own pace and limber up slowly. Moving about should be confined to Necessity only--get food, water, go outside.
Pain that worsens can indicate that something More Serious than a strain is going on: Lyme Disease, a ruptured disc, or an infection in the spinal cord, to name a few. If discomfort seems to not improve or gets any worse, a re-check appointment and some tests are in order.
Some areas have Veterinary Chiropractic or Acupuncture services available, your vet's office may know about this and can give you a local referral. Dogs have a very good response to this type of treatment.
In the meantime, allow your pet to rest as much as he likes...limit all activity that is not necessary, even when he starts to feel better, to prevent re-injury or exacerbated injury. These patients often have relapses periodically throughout their lifetimes, unfortunately, so you will always want to be somewhat careful of ambiguous situations (boisterous children or other pets), moving furniture, stairways, and early signs of discomfort.
You might try putting a Very Stable ramp at any stairs.
If you need to pick your dog up, scoop the chest with the whole forearm between the front legs...so he is lying on your forearm...and then let him "sit" on the other hand or forearm so that the back is a straight as possible and he can lean his shoulder against you if needed. Don't rush...let him settle as much as he can before lifting so that he gets the idea that you are trying hard to not jostle him. This can help him release his muscles instead of clenching them.
Medical approaches to pain are pretty varied, and vets use many kinds of medications to help these patients. Not every drug works for every individual, so keep in close contact with your vet's office.
Wobbler's Syndrome is a kind of catch-all term for a number of problems that cause physical symptoms from the nerves inside the vertebrae of the lower neck. These problems can be inherited, caused by trauma, infection, malformation of vertebral bones, or age-related degeneration of the vertebrae (for example, arthritis, tumors of the spinal cord, or bone cancer). Arthritic changes taking place in middle-age will worsen any problems that already existed in a younger dog.
Young dogs and older dogs can both be presented for examination of signs associated with this syndrome depending on the source of the nerve damage. Larger breeds are much more often seen for diagnosis and treatment, but smaller dogs can develop the acquired forms due to injuries to the neck bones.
Most often, one of the first signs seen at home is weakness of the hind legs, or even of all four limbs. This is a progressive illness, time is often of the essence.
Treatment depends on the cause of the syndrome; the diagnosis of a cause usually involves equipment found at a Veterinary Neurologist's office. If surgery is needed, a specialist should be the person to perform the procedure. The success of treatment(s) depends on the original source of the compression of the cervical (neck) nerves. A specialist would be best able to tell you what success treatment(s) would have in your dog's case.
If your dog is experiencing severe symptoms...if he/she cannot stand or walk, for instance, he/she should be seen by a specialist immediately.
Is My Dog Senile???--Canine Cognitive Dysfunction
Dogs can develop a number of neurologic side effects from illnesses such as hypothyroidism, liver or kidney disease, Cushing's Disease, and diabetes. These illnesses are diagnosed by having some blood tests run, and should be ruled out first in any case of an adult or geriatric dog showing abberent behavioral changes not associated with environmental factors. Slow-growing brain tumors can also lead to strange changes in behavior and temperament.
There is also now what we have come to know as a kind of dog senility called Canine Cognitive Dysfunction, also called Cognitive Dysfunction Syndrome (CDS).
Symptoms include loss of attention to familiar people, failure to concentrate, difficulty with holding urine or stool (including voiding in the wrong places and/or not alerting you to their need to go outside), and other strange behaviors such as standing in a corner all day, going to the food dish and not eating, inappropriate aggression, or getting "lost" in familiar surroundings...people have told me of pets trying to sleep in the bathtub, or "nesting" under furniture! Symptoms are often worse at night, some dogs even switch their entire day-night schedule or cry all night.
CDS seems to be caused by a decrease in a brain hormone and can be treated by giving a medication called L-deprenyl (the human generic "selegiline" is very affordable). This condition is progressive and worsens over time; treatment can reverse early signs and slow down the damage so that a dog can live a more normal geriatric life, but the lifespan is considerably shortened as brain systems progressively shut down and become increasingly dysfunctional.
Diagnosis is based on symptoms and testing to rule out conditions listed above, then response to medication is used to guide treatment. Gaining additional quality time together can be an invaluable contribution to any human-canine bond facing end-of-life issues.
Talk with your veterinarian as soon as possible about any case of sudden behavioral changes in a pet so that you will be able to get answers and support quickly!
Canine Parkinson's Disease?????
Parkinson's Disease is a human neurologic condition that produces, among other things, a pronounced muscle tremor when the body is AT REST...something quite unique and distinct from muscle tremors produced during movement.
There are a lot of conditions in humans and canids that can cause a muscle tremor.
1) Excitement is mediated through the brain by chemicals such as serotonin and norepinephrine. It is possible for a dog's system to either produce too much excitatory chemicals, or to be especially sensitive to their presence. Very prolonged "firing" of nerves in the muscles can cause discomfort. Excited shivering can be considered normal in the absence of other symptoms of illness, and is ordinarily seen throughout a dog's lifetime beginning in puppyhood.
2) Pain in the joints associated with injury, arthritis or other degenerative bone diseases can cause the excitatory system to become over-active, due to the body's response to stress and exertion.
3) Tumors growing in the brain and/or spinal cord can press on nerves that control muscle movement. Other structural problems, such as severe arthritis or disc degeneration can cause severe nerve compression as well. These compressions can become serious enough to cause paralysis of one or more limbs. "Wobblers" is a condition that can appear in predominantly large breed dogs wherein the spinal cord bones in the neck interfere with signals to the lower body...shaking ("wobbling") in the hind legs is the most commonly seen symptom.
4) Degenerative conditions in the nerves and muscles themselves are often to blame in older dogs: these conditions are accompanied by reduction of muscle mass in the affected body part(s)...check your pet for thinness and boniness over the head and along the length of the legs: this muscle wasting often occurs slowly over time and can be missed. These nerve conditions are collectively called Myelopathies...many are autoimmune in origin, but some can be due to Fibrocartilaginous Embolism in the spinal cord.
5) Geriatric dogs that have trouble keeping up their routines around the house may be suffering from a degenerative condition known as Canine Congitive Dysfunction...a kind of dog senility that may be helped with early drug intervention.
6) A Parkinson's-like degenerative condition has been identified on the genome of Chinese Hairless Crested Dogs. Now research specificallly for dogs has a starting point.
7) Occasionally, we still do not know what causes these symptoms in pets --Idiopathic Tremor--in this way, there is similarity to Parkinson's only in that more research is needed over time to find the root cause(s).
Approaches to treatment vary, depending on the root cause of the tremor and the familiarity of veterinary support...with more complex disease, a consultation with a Veterinary Neurologist is often helpful and most direct.
Canine Brain Stroke? Old Dog Vestibular Disease
Strokes are much more rare in pet dogs than they are in people and less often to blame for strange symptoms we see in our older friends. MRI scans are needed to confirm the presence of bleeding blood vessels in the brain 100%. These scans are performed under general anesthesia in veterinary medicine.
A number of more common things can cause a disturbance of the "vestibular" system in the brain, which is responsible for balance, among other things. These conditions include: ear infection, cancer, OR contamination of the brain with waste products usually handled by healthy kidneys and liver.
The chance of more severe problems increases with increased age of your dog.
Symptoms of vestibular disturbance include rapid eye movement from side-to-side, inability to stand or walk due to dizziness, nausea and/or vomit (with refusal or inability to eat), spastic head movements, and a tilt in the orientation of the head. Affected dogs prefer to lie on one side of the body only, and may experience paralysis of certain muscles on the affected side of the face and body.
There is such a thing as Idiopathic Vestibular Syndrome...(idiopathic=pathology or illness which doesn't make sense)...which does not have a cause that we can find. This is pretty common in middle-aged and older dogs. The most severe symptoms fade (or become adjusted to!) over the course of a few weeks, and the most prominent thing we see is the head-tilt...looks weird, but is not a serious problem long-term. Many veterinarians refer to this condition simply as Old Dog Vestibular Syndrome.
Medicines can be given to relieve bothersome syptoms like vertigo and nausea...these are antihistamines like meclizine or diphenhydramine. Some dogs are given steroid drugs if more serious inflammatory or tumor conditions are suspected.
If your regular veterinarian cannot help you find out what has happened, and your pet continues to have severe symptoms after a few weeks, you may be referred to a Veterinary Neurologist, a specialist who has been trained in the conditions that affect the nervous system in pets.
How to Help Your Vestibular Dog at Home:
1) Call your vet's office as soon as possible so that a certain diagnosis can be made, and medicines prescribed to reduce severity of symptoms.
2) Protect your pet from staircases, slippery floors and other hazardous areas of the house where falls can happen.
3) Small dogs can be lifted and carried from place to place...these patients prefer to be carried in a bit of a C-shape, with the "bad" side of the body held against you (this is the side that your dog lays Down on).
4) Large dogs can be assisted with a strong towel as a sling under the hips...go very slowly and stop for rests when needed.
5) A dark environment can make dizziness worse, so keep "night lights" on throughout the house during nighttime hours so that your pet does not get more dizzy if he/she wakes in the dark.
6) Feed bland liquid or softened foods by hand until your pet feels able to pick up and eat foods without assistance...keep water in a no-tip container near at hand.
Encephalitis
Encephalitis is the medical word to describe inflammation and swelling of brain tissue. A variety of symptoms of brain dysfunction can be seen, including motor (movement) problems and coma.
Mosquito-borne infective agents (many viral) are most prevalent in the southeastern U.S. (where mosquito populations are most stable all year round). There are various organisms that can affect many mammal species (and even reptiles!).
Other causes of encephalitis include dog-borne illnesses (such as canine distemper virus), and infective agents carried by ticks.
The most common cause of encephalitis in pet dogs is an immune condition. Treatment is available and is very effective if started early enough.
Pug Dog Encephalitis
There is a terminal condition that is genetically inherited in Pugs as an autoimmune illness, commonly known as Pug Dog Encephalitis. In order to assign this diagnosis to a case, the dog should be younger than 6 years of age at onset.
Little is known about how this condition develops to the brain-damaging phase, so treatments are confined to controlling symptoms until a "point of no return" is reached in the disease's progression.
Lissencephaly
Lhasas and people share this affliction of the developing brain that accounts for symptoms in growing youngsters. The normal mammalian brain develops an elegant pattern of convolutions and waves in the outer cortex...this is in contrast to the smooth contours of the inner brain matter.
Sometimes, due to genetic or other developmental problems (including exposure to certain plasticizing chemcials), these folds do not form and the outer brain tissue remains smooth (greek: "lissos"=smooth, "enkephalos"=brain).
Unfortunately, the folded landscape of the motor cortex is quite vital to normal brain and body function. Very young infant pups seem completely normal, but will reveal problems as they grow. By four months of age a syndrome emerges that can include: blindness, aggression, seizures, uncoordinated movements (including problems eating and walking), inability to house-train and other learning disabilities.
Although many people may decide to cope with some--or indeed many--of these problems, aggression is the most common cause of eventual euthanasia. Since there is no way to correct lissencephaly, euthanasia is a perfectly reasonable choice...if a pup is living in a constant state of high agitation, we can assume that there is suffering.
Although not all human cases are genetic in origin, we must assume that breeding parents of affected pups will result in more affected litters over time. As difficult as it is, I urge all breeders to remove all genetic stock from their breeding programs if this illness is found in any pups.
