The nervous system is composed of the brain, the spinal cord and all the nerves and branches which connect with the tissues and organs of the body. The brain is like the "command center" where the animal reasons, perceptions of the outside world are interpreted and activities are coordinated. The spinal cord is like the main phone line where the functions from the brain are carried to more distant areas in the body, and all the peripheral nerves, with numerous branches from these two organs, act as the final pathway between the nervous command centers and the tissues.

The brain and spinal cord make up what is known as the Central Nervous System. All other nerves make up the Peripheral Nervous System. Another common subdivision given to the nervous system is that of the Voluntary and Autonomic Nervous Systems. Some areas of the nervous system are concerned with conscious, voluntary activities such as walking or barking, while other areas handle all those functions we and our dogs never think about, like the production of urine or the digestion of dinner.

Nervous tissue, like all other tissues in the body, is subject to insult and damage, but unfortunately, severe damage to the nervous system often cannot be repaired and permanent dysfunction may result. In other cases, damage to surrounding tissues may impair neurologic function, but when healed or repaired, no long-lasting damage is apparent.

With the exception of traumatic peripheral nerve injuries, diseases of the nervous system are uncommon, comprising probably only 1% of all disease problems encountered by veterinarians. Most general practice veterinarians can diagnose the signs of neurologic disease, but many lack the special equipment and training needed to establish a thorough diagnosis. Fortunately, larger cities have veterinary neurologic specialists who have the capabilities to diagnose these less commonly seen conditions.

A seizure is defined as a period of abnormal electrical activity within the brain, with the seizure actually being the symptom of this dysfunction not an actual disease. While most people think of a seizure as the dog falling over and flailing about wildly, in actuality there is great variation in the presentation of the seizure and/or its severity. The term Epilepsy is used to define recurrent seizures regardless of their cause; the term Idiopathic Epilepsy defines recurrent seizures of unknown origin.

Causes of seizures can include rabies, distemper, toxoplasmosis, encephalitis, systemic fungal disease, trauma of the brain, low blood sugar, liver disease, kidney disease, and poisons among other causes. As previously mentioned, the cause may not ever be determined.

The clinical signs of a seizure disorder include an Aura or PreIctal phase when the dog may sense the seizure is about to happen and become restless, hide, seek comfort from its owner, or cry out. Ictus is the term for the actual seizure. While most owners will report that the seizure seemed to last a long time, in actuality most seizures last less than 2 minutes. Most dogs will have some variable degree of abnormal consciousness and loss of normal muscle tone including involuntary muscle movement, salivation, loss of bowel or bladder control, altered sensation and often altered behavior. A Post-Ictus phase will be the period of recovery lasting 30 minutes to an hour, where the dog slowly regains normal strength and mental status. Some dogs may appear blind and weak during this phase.

Other seizure classifications that are important to understand are Cluster Seizures, when two or more seizures occur within a 24 hour period, and Status Epilepticus; seizures that continue for 30 minutes or more without stopping. These would generally be the only situations where the life of the patient may be in jeopardy. In most cases, seizures will be infrequent and cause little harm to the dog. Your veterinarian should, however, properly investigate all seizures. If the cause is secondary to some other condition, resolution of that disease will generally prevent further seizures.

When the patient is having seizures and the cause is undetermined or otherwise unknown, then it can be said that the patient is Epileptic and the treatment, therefore, is to control the abnormal brain activity. In most cases when seizures are mild, short, and infrequent, it may be in the dog's best interest not to treat as there may be more complications from daily medication than from a few occasional minutes of altered consciousness.

Two other variations of seizure disorders are commonly recognized and classified as Sleep Disorders. Narcolepsy is excessive sleepiness during waking hours and may be very difficult to diagnose without other symptoms. Cataplexy is a disorder where quickly and briefly the muscles become paralyzed and normal reflexes are lost. Dogs may be awake when this occurs. Most commonly attacks happen after the animal has been very active or highly stimulated. Diagnosis is difficult and oftentimes complicated; several other diseases may produce similar signs. These conditions, however, are rarely life threatening.

In diagnosing seizure disorders, historical information including accurate descriptions of what occurs with each episode is very important. A complete physical and neurological exam followed by blood counts and serum chemical analysis is usually performed first. X-rays, CAT scans (where available), spinal fluid taps and analysis, and electroencephalograms can all also be used to pinpoint the nature and cause of the seizures.

As previously stated, if an initiating cause or other disease is identified, that is treated first if possible. In cases of recurrent seizures of unknown origin, called idiopathic epilepsy, it is important to understand that the ultimate goal of treatment will not be to prevent another seizure but to decrease the number of seizures as much as possible, to minimize the severity of any seizures and to increase the interval between any seizures with minimal side effects. Most veterinarians will be slow to start any therapy when few seizures have been observed, when the episodes are far apart and when the seizures are mild.

Drugs like phenobarbital, primodone, potassium bromide, diazepam (Valium) and phentoin are all employed, with phenobarbital being the drug most commonly used and the most effective. Dogs with sleep disorders are treated with imipramine, yohimbine, methyphenidate (Riatlin) or dextroamphetamine. Sometimes combinations of medications are needed to effectively control the problem. As metabolism of these drugs can vary and change over time, the dose of medication and the mixtures used may also change over time.

It will be important for your veterinarian to monitor blood levels of medication to insure proper dosing and other blood testing will be needed to rule out the presence of liver, kidney or other organ dysfunctions. It is uncommon for patients to stop taking medication after it is begun so do not stop giving the prescription unless the doctor feels that this is in the best interest of the dog.

By definition, this condition is caused by protrusion (bulging) or extrusion (rupture) of disc material from the intervertebral discs against spinal nerves or the spinal cord. The condition occurs secondary to degeneration of the disc, most likely as a response to abnormal or excess forces (traumatic episodes, even slips and falls) on the back. Jumping up and down off couches and the like, climbing stairs, hard rough-and-tumble play are all activities that over time are thought to accelerate disc degeneration.

Certain breeds due to their "design" are much more prone to disc problems including the Dachshund, Bulldog, Pekingese, Cocker Spaniels and Beagles. Other small breeds, those that tend to be up and down off furniture all the time, will also be prone to this problem. Overweight and obese dogs will also be at greater risk. It is this author's opinion that in many milder cases of back pain, disc protrusion is not present and that malalignments of the spine cause similar clinical signs without actually being a "disc disease".

Clinical signs, which can occur in younger dogs of susceptible breeds and older animals of any breed, include pain that may come and go, pain when being touched or lifted or spontaneously occurring pain episodes. The posture of the dog may be altered depending on what area of the back is affected, and the dog may resist certain movements or be reluctant to perform everyday activities such as jumping onto a chair or ascending the stairs. Some dogs may be in so much pain as to unexpectedly bite, even before being touched.  ((Disc Disease))  ((Disc Disease 2))  

If the spinal cord has been damaged, the dog may appear weak, stagger, or even become paralyzed with leg, bowel and bladder functions being lost. Some dogs may become paralyzed and even loose all pain sensation, thus indicating far worse damage to the spinal cord. Any signs of unexplained pain or paralytic type signs should be investigated as quickly as possible. Diagnosis is based on historical information, clinical signs, X-rays and myelography, which involves injecting dye into the spinal cord then taking X-rays.

After careful evaluation, treatment will vary depending on the severity of the symptoms. Dogs that become acutely paralyzed or deteriorate over a short period of time will need more dramatic treatment than those who are mildly painful.

Many dogs do well with injections of cortisone, banamine or similar agents.  Rimadyl, deramaxx, previcox, zubrin or cortisone type drugs are employed to relieve pain and neurologic swelling. Muscle relaxants such as robaxin or diazepam often help greatly to relieve muscle spasm. Strict rest and confinement is highly recommended to prevent further damage and allow healing to occur. Many dogs benefit from physical therapy, and spinal manipulation has been used in many cases with good results. Massage and heat and cold therapy may also be of benefit.

Dogs that become paralyzed present a dilemma as to what therapy to use. Many of these dogs need surgery to relieve compression on the spinal cord. Some, however, will not be cured with surgery, while others MAY recover without surgery. The obvious problem, even with the best diagnostics, is that we cannot with perfect accuracy predict what patient will do best with which therapy. Dogs that need surgery but do not get it will generally remain paralyzed for life. In short, surgery should be considered in all patients with recurrent problems, severe pain or with paralysis.

Surgery for disc disease, depending on what area of the spinal column is affected, usually amounts to removing a section of one or more vertebrae to allow pressure to be removed from the spinal cord. This allows the surgeon to remove disc material where appropriate. As mentioned, recovery will vary with the degree of permanent damage to the spinal cord that has occurred. Manipulation and physical therapy after surgery is very important to speed rehabilitation.

In some cases of disc disease, small pieces of the inner portion of the intervertebral disc may enter the blood vessels and block blood flow to the spinal cord, thus producing a type of embolism. This would in many ways, be what we would term a "stroke" that occurs in the spinal cord. This can occur in any dog and is more common after a traumatic episode.

Clinical symptoms include a very sudden onset of partial or complete paralysis of one or more areas of the body. The symptoms are often asymmetrical meaning that one leg may be badly affected while the other leg is normal. Rarely does the severity progress after initial onset, and usually there is no lasting pain. In several ways, this condition will mimic cases of intervertebral disc disease. Diagnosis is based on history, physical and neurologic examination, X-rays, CSF taps, and myelography.

Once blood flow has been blocked to any part of the nervous system, damage usually occurs quickly, so treatment is centered on minimizing and reducing swelling and further damage to the cord. Intravenous cortisone and fluids are used for stabilization. Other medications to prevent vomiting and also control swelling may be indicated. Long-term physical therapy and a little good luck will determine long term outcome, which varies with the overall severity of damage.

This condition causes spinal cord compression secondary to instability between the first and second cervical vertebrae (atlas and axis). Occurring in any breed, this condition may be congenital or secondary to trauma. Congenital cases will generally be noted under one year of age, while traumatic cases can occur at any age.

Clinical signs include severe neck pain with the neck being held straight and rigid in most cases. Some variable degree of staggering and paralysis is usually also noted. Most dogs seem weak in all four legs, perhaps worse in the hindlegs. Clinical signs may be confused with that of intervertebral disc disease. Diagnosis is based on clinical signs and X-rays taken under anesthesia. On some occasions, a myelogram may be needed to illustrate the cord compression.

Without question, surgery is the only option to stabilize the excessively mobile vertebrae and stop further cord damage. Some dogs may also require removal of a section of these vertebrae to further decompress the area. This surgery can be risky and should be performed by a specialist with experience in doing the procedure. Some type of external braces and wraps may also be needed, with the patient being kept heavily confined for several months post surgery.

This condition occurs when the spinal cord becomes compressed due to a malformation or a malarticulation (where the vertebrae are not attached and moving one to another as they should) of the vertebrae of the neck. This is seen most often in large breed dogs, especially the Doberman Pinscher and the Great Dane. The cause is probably genetic with some interrelation of rapid growth and excess calcium in the diet contributing to the development of the problem. 

Some dogs (Danes) will develop clinical signs at less than 2 years of age, while others (Doberman) don't show symptoms until 3-9 years of age. Males seem to be affected more often than females. Clinical signs usually appear suddenly and worsen quickly, often after some everyday trauma exacerbates the condition. Dogs will stagger or have trouble controlling all 4 legs (thus the term "Wobblers") and may even become paralyzed in all 4 legs and loose bowel and bladder control. The severity varies from dog to dog.

Diagnosis is based on clinical signs, breed and historical information, X-rays and myelography (putting dye into the spinal canal). This condition mimics several other disease states and can easily be confused with disc syndrome or DJD of the hips. All cases in which spinal cord function is altered or damaged will present with the signs of weakness, ataxia (staggering) and possibly paralysis. Treatment should be undertaken before paralysis is present for optimal results.

Some dogs may be treated in a conservative manner; being rested and confining the dog with the administration of cortisone-like drugs to minimize neurologic swelling. In most cases, however, surgery to decompress the spinal cord by opening up a section of the vertebral column and stabilization of any "loose" areas with some type of fixation device us usually needed. The prognosis for dogs that have mild symptoms is usually good, but those who become paralyzed or have multiple problem areas in their necks will often not do well.

This condition is also characterized by compression of the spinal cord, although only towards the back or tail end of the dog, with resulting loss of hindleg function and possibly bowel and bladder control. The condition usually affects large dogs and is caused by a narrowing of the spinal canal at the point where the spine joins the pelvis (lumbosacral joint). There may be no apparent reason for this narrowing, or subluxation of the lumbosacral joint, trauma or congenital defects may all lead to the condition. ((Lumbosacral Spondylopathy))

Most dogs are older when they start to show symptoms, and they will exhibit pain in the hindend, especially when rising or when touching the area. Signs may include lameness and pain in the hindlegs, and a tingling sensation may cause some dogs to chew and mutilate their tails. The tail may also loose sensation and/or function and loss of bowel and bladder control is not uncommon. Diagnosis is based on these clinical signs, X-rays, physical examination and in some cases myelography.

Dogs with mild to moderate pain and little or no paralysis can be treated with rest and strict confinement for a week or two, and Rimadyl, deramaxx, previcox, zubrin, meloxicam and cortisone have all been used for pain. Dogs that improve may still need treatment on and off when symptoms reappear. Animals with progressive symptoms, paralysis and/or loss of bowel and bladder control should have surgery. Some dogs have responded to spinal manipulation.

Surgery is similar to that of other spinal compression; removal of a portion of the vertebra over the sight of cord compression to relieve that increased pressure. Usually a surgical specialist will be required for such a procedure, and most dogs do well if operated on long before the signs become too severe. Some dogs may take months to completely recover.

Discospondylosis is a non-inflammatory condition affecting the mid to low back areas of the dog. If areas of the spine become unstable or malarticulated (not moving/functioning properly) the body will try to stabilize the areas by building calcified "bridges" between the areas of instability. Unfortunately, this will ultimately serve to limit spinal mobility and function. 

The condition may be caused by a congenital weakness of the spine, traumatic episodes including multiple small traumas over time as in a dog that jumps or rough-and-tumbles repeatedly. Often there is damage or stretching to ligaments which help hold spinal continuity which thusly leads to the mentioned instability. Clinical signs may include low back pain, stiffness, trouble rising and walking and other deficits, especially if some degree of intervertebral disc disease is also present.

The signs of this condition rarely appear until the dog is older; they are usually insidious in their presentation and slowly progressive. Larger active breeds are most commonly affected. Some dogs may have evidence of this condition on X-rays without any clinical signs whatsoever. Diagnosis is based on history, clinical signs, and X-rays.  ((Spondylosis))

Unfortunately, by the time of diagnosis, the damage and progression of the disease may be moderately advanced and irreversible. Weight loss in obese dogs will be very important, controlled moderate exercise where no trauma can occur (i.e. no jumping for the Frisbee) will be important, and Rimady, Deramaxx, previcox, meloxicam and other NSAIDs as well as cortisone can all be used for pain relief. Some pets may benefit partially from spinal manipulation and the use of chondroregenerative products such as Adequan, SynoviCre, Cartiflex, Cosequin and Cartiflex; the absolute benefit of any of these is undetermined. It is unlikely to cure these dogs, but many dogs will do quite well with the treatments outlined herein when used in combinations. Some dogs receive benefit from chiropractic manipulation, acupuncture and general physical therapy.

Diskospondylitis is an infection of the intervertebral disks and related vertebrae (osteomyelitis). Most are caused by bacteria but systemic fungal disease can also affect the spine. Infections in other areas are thought to spread through the blood and attack these areas. The bacteria Brucella canis should be considered in all cases, with specific testing being performed.

The disease occurs more often in large breed male dogs of middle age. Clinical signs include pain, fever, altered gait, lethargy, poor appetite, weight loss, staggering and some variable degree of paralysis. Diagnosis is based on clinical signs, X-rays, blood culture, complete blood counts, brucellosis testing, and in some cases a spinal fluid analysis (CSF Tap). Symptoms are often similar to other spinal cord diseases.

In dogs with minimal neurologic deficits, antibiotic therapy may prove quite adequate and in all cases should be continued for 4-6 weeks. In all cases if possible, antibiotic selection should be based on blood cultures. In cases with neurologic deficits, spinal surgery to decompress affected areas of the spinal cord may be needed, plus surgical cleaning of damaged areas in the vertebral bones. X-rays and cultures can be used to follow the healing process and determine when a cure has been obtained. Dogs that are brucellosis positive should be spayed or neutered.

This is a slowly progressive deterioration of nerve function beginning at the tail end of the dog and moving towards the head. There does seem to be a predisposition for German Shepherd dogs and their crosses, which may suggest a genetic cause.

Clinical signs usually begin between 6-11 years of age. Slowly, the dog will stagger and become partially paralyzed in the rear legs which becomes worse with time. Diagnosis is based on history, clinical signs, physical exam, neurologic examination and X-rays. Many dogs are erroneously diagnosed as arthritic so a thorough work-up is essential for proper diagnosis.

There currently is no known successful treatment for this disease. Cortisone, aspirin and other painkillers are sometimes used but do not alter the progression of the condition. Spinal manipulation and acupuncture have both been tried but no scientific studies support this treatment. Some dogs do well in a "cart" once they are immobile. Some new evidence suggests that certain supplements may arrest or even reverse the course of this illness.

Occasionally and most often by accident, it is discovered on X-rays that some dogs have abnormal vertebrae. In most cases these are incidental findings neither doing the dog harm nor causing any pain. In some rare cases, signs similar to those of intervertebral disc disease can occur due to spinal cord compression and treatment should be accordingly. Several common abnormalities include:

HEMIVERTEBRA; wedge-shaped vertebra. ((Vertebral Defect))

BLOCK VERTEBRA; fusion of two or more vertebral bodies.

BUTTERFLY VERTEBRA; a cleft or fissure along the side of the vertebral body.

SPINA BIFIDA; an absence of the top arch or a cleft along the vertebral midline through which the spinal cord may or may not protrude.

Inside the brain and spinal cord, there is a system of passageways and ducts, which distribute fluid throughout the nervous system. (Cerebral Spinal Fluid) Hydrocephalus denotes an excess accumulation of fluid within the brain and almost always occurs as a congenital defect of young dogs, most often Chihuahuas, Boston Terriers and Pomeranians; the breeds, which have a large dome-shaped heads, are affected. As fluid accumulates inside the brain, normal brain tissue actually becomes compressed against the inside of the skull.

Clinical signs include a depressed mental state, weakness, hyperactive reflexes and blindness. Diagnosis is based on a typical history in a susceptible breed, physical and neurological exam and X-rays. Many dogs also have recurrent hypoglycemia (low blood sugar) so hydrocephalus should be considered in dogs that have repeat attacks of weakness. In most dogs, or in dogs that do not respond to treatment, the condition progresses and the pet will deteriorate and die from the pressure within the brain. ((Hydrocephalus))

Some dogs may receive short-term relief from the administration of cortisone. The only true and lasting treatment, however, would be to have a shunt (artificial tube passage way) installed to allow fluid to drain. A surgical specialist trained in this procedure must be sought as the procedure is somewhat risky. Some dogs may develop seizures and these too must be managed with the appropriate medications.

Encephalitis is inflammation of actual brain tissue, often caused by some infectious organism. (bacteria, fungi, viral) Meningitis denotes inflammation of the membranes that surround the brain (and spinal cord). These type infections are uncommon but most often associated with diseases that affect multiple body systems such as distemper, rabies or ehrlichiosis.

The clinical signs of brain disruption are considered to be multifocal. This means that depending on which area(s) of the brain (and possibly spinal cord) are affected and how severely will determine what manifests outwardly. This also makes describing what symptoms a dog owner would see quite difficult, as they will be different in every case.

In general terms, clinical signs may include seizures, altered consciousness, loss of vision, partial or complete paralysis, head tilt, altered reflexes, coma, staggering, twisting of the body, neck pain and neck tension. Fever and disease symptoms relating to other body systems are also possible, such as a respiratory disease along with canine distemper. Many times these symptoms get worse day by day.

Diagnosis is difficult, and based on history, physical and neurological signs, complete blood counts and serum chemistries, serological tests for specific diseases, CSF fluid analysis, X-rays, and blood or CSF cultures may all be needed to pinpoint the cause and direct treatment. Many cases of suspected meningitis/encephalitis would be best treated by a veterinary neurologist who specializes in these difficult conditions.

As in any case, if it is possible to identify the cause of the infection and destroy it, the best result may be had. Most bacterial infections can be treated with antibiotics, fungal infections with antifungal medications, but viral infections have no specific treatments yet. Fluid therapy to combat dehydration, antiseizure medication as needed, furosemide or mannitol to combat swelling are all commonly employed.

Once damaged, neurologic tissue rarely is repaired, so permanent alterations to mental state, functional impairments or seizure disorders can all be after effects. Most patients will need long term treatment to even begin to see a recovery, so commitment and patience are essential. Physical rehabilitative therapy should not be overlooked, nor should good nursing care and TLC for these patients.

Meningitis is inflammation of the membranes around the spinal cord. Myelitis is inflammation of the solid matter of the spinal cord, and Meningiomyelitis is inflammation of both areas combined. Infectious bacteria, fungi or viruses may be involved as may parasites, trauma which exposes the nervous system to outside environment, immune-mediated diseases, among other causes. Many times infections get to the nervous system after first starting out in some other area and traveling in the blood to this site.

Pain over the back or skin is quite a common sign with most dogs being stiff, have trouble moving, fever and some dogs may stagger or be paralyzed to some degree. Other signs may come about as the brain becomes involved which can also easily occur. Seizures too may be present. Most dogs get worse over a few days time. Diagnosis is based on history, physical and neurological examination, blood counts and serum chemistries, CSF fluid analysis and cultures, and X-rays. Diagnosis is difficult, often with the help of a veterinary specialist being needed, and the symptoms often initially appear similar to several other more common neuromuscular diseases.

As with infections of the brain, an accurate diagnosis, obtained as expeditiously as possible will be essential to being able to provide proper treatment and limit the extent of permanent irreversible damage. Most bacterial infections can be treated with antibiotics, fungal infections with antifungal medications, but viral infections have no specific treatments yet. Fluid therapy to combat dehydration, antiseizure medication as needed, furosemide or mannitol to combat swelling are all commonly employed. In most cases cortisone is avoided as it may allow certain infections to get worse.

Most cases are treated in the hospital while on intravenous fluids and general supportive care as most medications are best given intravenously and often in a continuous nature. Most patients will improve and progress based on the bottom-line cause, i.e. if it is a treatable illness and the extent of damage placed upon the nervous system. Unfortunately, it is impossible to predict outcome before treatment is begun, and even severe cases may completely improve.

A frustrating problem, dogs with this condition will suddenly and without warning will show signs by becoming very unstable, stagger when they walk or are unable to walk at all, have eyes which roll back and forth as the dog lies (tries) still, have a head tilt or they may roll about. Often owners will think their pet has had a "stroke", but research has shown this is not the case. The problem seems to lie in a dysfunction of the vestibular mechanism, that part of the inner ear that helps the dog maintain his body and movements in relation to gravity. Dogs with this condition are literally motion sick and some will vomit repeatedly.

Most dogs are older, thus the term Geriatric Vestibular Syndrome. Diagnosis is based on history and physical examination with X-rays, blood counts and CSF analysis all being needed to rule out other neurologic conditions, especially inner ear infections.

Some doctors advocate no treatment other than supportive care as many cases get better in a week or two. Antibiotics for possible inner ear infections, cortisone like drugs and Dramamine for the "motion sickness" are all often used to improve patient comfort. Most dogs do well given the time to improve, although some will be left with a permanent head tilt towards the damaged side.

Vascular injury to the brain or spinal cord occurs when either blood flow is blocked, known as an Infarction, or when bleeding occurs inside the brain, known as a Hematoma. Most infarcts are caused by hypothyroidism, heart disease, clotting disorders, thromboembolism, endocarditis or inflammation in the blood vessels secondary to infectious diseases. Hematomas are most commonly caused by clotting disorders.

Most often strokes will occur in older animals unless infectious organisms are involved. Usually clinical signs occur very suddenly and often are quite severe but will stabilize, in most cases, over a few hours or days. The exact clinical signs will once again vary with what area in the brain or spinal cord is damaged, but will usually be asymmetric, meaning one side or area or function(s) will be affected while others on another part will seem normal. Most dogs will do better with time, but it is hard to predict what the final outcome will be.

Diagnosis of vascular injuries is based on the history of a sudden neurologic malfunction, physical and neurological examination and ruling out other disease processes with blood tests or X-rays. Neoplasia of the nervous system, idiopathic vestibular syndrome and trauma to the brain or spine can all mimic this condition. Seizures can also occur secondary to vascular injuries.

As with any condition, if an exact cause can be had and treated, the chances of a good outcome are generally increased. If the cause is unknown, symptomatic and supportive care is best. Many veterinarians will use cortisone type drugs to minimize brain swelling. Antiseizure medications are used to control seizures, and supportive care such as intravenous fluids and feeding are needed until the dog is able to walk and take care of itself are highly recommended. As in people, we are hard pressed to predict the absolute final outcome of most of these cases so we must try to help the patient survive so that healing can occur.

A neuropathy refers to a physical and/or functional change to nerves that carry information to and from the brain and spinal cord. A polyneuropathy simply implies that several or multiple nerves are affected, often effecting both sides of the body or section of the body equally. Another term used to describe this condition is Peripheral Neuropathy.

There are many different and varying types of polyneuropathy; most of which are so rare that we feel detailed description of each is impractical. Often a veterinary neurologist is needed to make the diagnosis, let alone identify an exact cause or syndrome. Some polyneuropathies will be acute, manifesting very suddenly, others will have a gradual onset and progressive course.

Clinical signs will depend on which nerves are affected and in what region of the body but may include weakness, paralysis, loss of muscle mass (atrophy), reduced muscle tone, poor reflexes, sensitivity to pain/touch or loss of sensation, self-mutilation, altered gait and loss of recognition as to limb position (proprioception).

Diagnosis is based on history, physical and neurologic examination, complete blood and serum chemistries, muscle and/or nerve biopsies and other special nerve testing. Again, most often a specialist will be needed to make the absolute diagnosis. One specific type of polyneuropathy occurs secondary to diabetes mellitus, known as Diabetic Polyneuropathy.

It is thought that alteration or degeneration of insulating cells along nerves occurs in dogs with Diabetes and clinical signs most often including weakness, loss of muscle mass and increased sensitivity, all most often occurring in the hindlegs and pelvic area. Treatment of this type of neuropathy relates most specifically to treatment of the primary condition.

While supportive and symptomatic care can be given to all dogs stricken with these conditions, an accurate diagnosis is essential to long term therapeutic success. As some polyneuropathies are immune-mediated, cortisone and similar agents may be helpful.

As many dogs become paralyzed or are quite weak, heavily padded beds or water beds along with frequent attention and physical therapy to keep muscles stretched and joints limber is very important. Some dogs will have trouble with bowel and bladder function and need assistance. Proper and adequate nutrition is also essential. Some animals, depending on the condition will recover with time; others may never recover.

Originally thought to only affect dogs that had been bitten by raccoons, this condition affects many different breeds that may or may not have ever even seen a raccoon. Clinical symptoms include a sudden severe weakness and loss of reflexes in the hindlegs of the dog, with total paralysis of all four legs occurring within 24-48 hours.

Dogs may also have respiratory paralysis, which causes death, or alterations in bark, bowel and bladder functions and severe generalized muscle atrophy. Diagnosis is based on clinical signs, neurologic examination, nerve conduction studies and CSF taps.

There is no treatment for this condition, but if the patient can be kept alive and well supported, most will recover in 3-6 weeks. The recovery will often be a "reverse" of how the symptoms started. The need for high quality and intensive supportive care cannot be overemphasized. Relapses are possible.

Certain species of ticks can secrete a toxin that interferes with nerve function. Clinical signs include staggering and weakness in the hindlegs that rapidly progresses to paralysis of all four legs. Pain perception is usually normal, but reflexes will be poor or absent. Dogs can die from respiratory paralysis. Diagnosis is based on history, clinical signs, finding a tick and response to removing the tick. ((Ticks))

Removal of any and all ticks is often curative with most dogs improving in 2-3 days. Supportive care until strength returns is essential as most dogs will need help eating, drinking and having bowel and bladder movements.

Myasthenia Gravis is a rare disorder of the peripheral nerves whereby the transmission of impulses between nerves and the muscles they attach to is blocked. This is an autoimmune disease as it is antibodies that attack and damage this junction between the muscles and nerves. The entire pathology of this disease is quite complex and is beyond the scope of this program; in some cases this illness can be congenital.

Most dogs will generally appear and act normal and then unexpectedly, signs of weakness, even to the point of collapse will occur. Some dogs may vomit, have trouble swallowing and drool excessively. Myasthenia gravis can be a cause of megaesophagus in the dog, and due to the difficulty swallowing, aspiration pneumonia can also occur. Diagnosis is based on history, physical and neurological examination, blood counts, serum chemistries, X-rays, and giving the drug edrophonium which produces a radical reversal of symptoms in dogs with this disease. (Which unfortunately lasts only a few minutes)

There are drugs including pyridostigmine, cortisone and a few other medications that can be used to control symptoms. Food should be fed in an elevated fashion to assist swallowing. Some dogs may have an enlargement of the thymus, a gland inside the chest, and these animals may benefit from removal of this enlarged organ. Dogs with this condition can be controlled and most do well a few months after treatment has started. Prognosis is fair to good depending on the severity of the condition.

Back to Dog Index

HOME PAGE | HOSPITAL INFORMATION | PET HEALTH INFORMATION

©2007 James W. Day D.V.M., P.C.