GSD myelopathy, also known as DM for Degenerative
(chronic and progressive) Myelopathy (spinal cord disease), is the first
disorder that comes to mind when German Shepherd Dogs and spinal lesions
are spoken of together. Almost peculiar to Shepherds, the first symptoms
are usually seen at about six to eight
years of age and have a duration of five to twenty-four
months, a bit longer if aggressive measures are taken. Initially,
the dog does not seem to realize what position his rear legs are in; soon
he will begin to drag his toenails and the top part of his paws, and may
tremble as if palsied. Eventually, he will be unable to get up on
all four legs, and by this time most owners will have decided upon euthanasia.
Symptoms and histological changes are very similar to those in multiple
sclerosis (MS).
First described as a specific, separate disease
in 1973, GSD myelopathy has been around a long time, but previously not
as well understood or distinguished from other pathologies. It gets
its common name from the fact that German Shepherd Dogs are found relatively
often, compared to much more uncommonly in a few
other large breeds. As a matter of fact,
the peculiar syndrome seen in our breed is also seen only (though rarely)
in the Belgian Shepherd and the Old English Sheepdog, and Dr. R. M. Clemmons,
neurology professor at University of Florida's veterinary school, feels
what is seen in other breeds may well be a different disorder. Those
other degenerative myelopathies are probably not caused by the same immune-system-related
deficiency as we have in the GSD.
Diagnosis is by the process of elimination, since
regular neurological tests aren't definitive, except for the presence of
a brain fluid protein in the lumbar area of the cord. Your best bet
would be to consult an experienced breeder who's been through it with his
own dog or dogs, and use the local vet for confirmation and medication.
He will see what you have: the dog atrophies in the haunches and croup.
Autopsy will not help you or your dog, but would find the obvious demyelination
(loss of the insulating sheath) of the spinal cord, destruction of some
large axons (nerve cells leading from the cord to smaller branch nerves),
and
abnormal cells (or certain cells in abnormal
locations). Similar signs may be seen in the brain's white matter,
and plasma cell infiltrates in the kidneys and intestines give further
evidence of the immune system failure at the root of this disease.
Since GSD myelopathy is so similar to multiple sclerosis, perhaps it would be worth trying the nutritional approaches used by some who treat that human disorder. Wheat germ oil contains octocosanol, a fatty or waxy high molecular-weight alcohol also given to patients with encephalitis and cerebral palsy, and also contains linoleic acid (as do several vegetable oils). But one fatty acid, docosahexanoic acid, is not at all abundant in normal diets, yet seems to be the first one depleted from the nerves' myelin sheaths in such disorders as MS. In many diets for MS patients, foods such as sardines and mackerel are emphasized, because they are among the very few foods that can supply this compound. Of course, vitamin B complex high in inositol, B6, B12, and choline is also highly recommended as an adjunct to vitamin E for nerve-muscle disorders. Since only a percentage of patients with MS or DM respond satisfactorily to a vitamin-only approach, the concomitant use of drugs and exercise should always be prescribed. As of this writing, there were three FDA-approved drugs for MS that not only help manage symptoms but also appear to "impact disease course" in relapsing MS, according to the National Multiple Sclerosis Society. They are Copaxone (Teva Marion), Avonex (Biogen), and Zanaflex (Athena Neurosciences). Your vet would have to decide whether or not he wanted to "go off-label", since these have not (yet?) been approved for dogs.
For several years, there was no generally accepted
treatment, but as breeders became aware of the benefits of high vitamin
E dosages, the veterinary profession began to see its efficacy and the
relation to the immune system. When I first encountered it, I got
an extra one or two years useful life out of one of my dogs by giving him
800 units (IU) a day, plus vitamin C for its synergistic effect.
Years later it was discovered that 2000 IU of vitamin E daily, 500 mg of
vitamin C twice a day, and a high-strength vitamin B complex twice a day
is the best dosage. Vitamin E is an important nutrient with a number
of physiologic and pharmacological effects.
As an antioxidant it helps reduce oxidation of
fats and increases the production of HDL cholesterol. At higher doses
it decreases production of prostaglandins and has anti-inflammatory action.
There is no known side-effects to vitamin E at levels less than 4000-6000
IU per day (except in cats, where levels above 100
IU/day can create hepatolipidosis. In DM,
low serum and tissue concentrations of vitamin E have been observed.
I recommend that vitamin E be given to all German Shepherd Dogs.
For GSDs less than 2 years of age, give 400 IU of vitamin E daily.
For older GSDs, give 800 IU of vitamin E daily. If your dog develops
DM, then the dose of vitamin E should be increased
to 2000 IU daily. Dr. Clemmons recommends the vitamin E be dropped
temporarily to about 100 IU if the dog has to be given aspirin for any
reason during the treatment, and recommends that daily DEC (diethylcarbamazine)
replace the monthly heartworm medications ivermectin (Heartgard, Heartgard
Plus, Ivomec) and Interceptor because these increase immune responsiveness;
also use the DEC in place of styrid caracide or Filaribits. Personally,
I would simply stop all use of heartworm medication, because the dog with
DM probably isn't going to last as long as it takes for a case of heartworm
to become life threatening, anyway. Flea control should be limited
to Precor™ for the house, and carbamates or pyrethrin/pyrethrum on the
dog.
GSD Myelopathy" -- Representing a neuron (nerve
cell), which can be very long as in the peripheral nerves or very short
as in some brain cells. Most have myelin "insulation" covering the axons
which conduct electrochemical messages much the way electrical wires conduct
electricity in your house or appliances.
Sensory nerves have different endings than do
motor nerves, and one sensory ending may differ from another type.
Chemical-pharmacological treatment has largely
been via the use of aminocaproic acid, something my friend Wayne Riser
(founder of OFA) told me about many years ago. More recently, acetylcysteine
three times a day has found acceptance. It now appears the best treatment
is a combination of all three approaches,
along with exercise. Alternate day dosage
with a steroid such as prednisone, plus acetylcysteine, added to the aminocaproic
acid and vitamin formula, is enough to keep the dog owner very busy and
tied to the home, but it offers the best chance at reducing progression,
thus prolonging life considerably more than in the
past. The drugs should be given in liquid
form, mixed with a palatable solution such as chicken broth.
There are generic varieties available. Medication helps up to 80% of afflicted
dogs, especially if started early. Hydergine, a prescription drug derived
from ergot fungus, is being researched, since it seems to promote
nerve regeneration. For dogs with advanced
DM, Dr. Clemmons suggests trying 5 mg three times a day for at least three
months.
I mentioned exercise, and this is the third of
the four-part fight against the disease. Every other day, the dog
should be given at least 30 minutes of aerobic activity such as vigorous
walking or swimming; if you start late, build up to the strenuous level
gradually; if your dog can't do the most, do less, but make it regular
and
stretch the limits where you can. The alternating
days of relaxation are important for repair and renewal. If the dog acts
sore, give him the analgesic prescribed by your vet (after he has "read
up" on the interactions of medications in regard to GSD myelopathy.
The fourth part is stress reduction. The vitamin C, that
anti-stress vitamin, is there for a good reason,
but take steps to avoid stressful situations, including surgery; if the
dog needs surgery, make sure he gets the acetylcysteine as well.
Dogs with GSD myelopathy often develop lick granulomas, which are ulcerations or (if you are lucky) callous-like reactions of the skin to extremely frequent licking, sometimes chewing, at the location of a supposed itch. It is probably a case of the limb feeling as if it has "fallen asleep", to put it into terms familiar to human experience. The tingling sensation caused by incomplete and erroneous signals by the nerves serving that place is much like the irritation caused by an ant bite, or hairs out of place, or anything in between. In trying to lick it away, the dog actually softens and wears away the hair and skin. The best I could do for my dog was prick the vitamin E capsule, squeeze out a little for topical application to the granuloma, pop the rest into his mouth, and then give him some distraction such as go for a walk. These ulcers on the feet or elsewhere don't easily respond, but the battle must be waged if the dog's life and comfort are to be prolonged. The immune system insufficiency may be temporary, though it is more often just “managed” or covered up. It may limit itself to just one or two symptoms such as the biting/nibbling/licking.
The approach to treatment of GSD Myelopathy that is proposed by Dr. Clemmons is called "integrative treatment". It combines conventional pharmaceutical treatment with "alternative medicine" or "supportive therapy". Paraphrasing some of his comments might be helpful here. Conventional drug therapy (medicines) has been of little lasting help to patients with DM. However, the combination of exercise, vitamins, and certain drugs has delayed the progression of DM in many dogs. Treatment has been directed at suppression of symptoms, and since the cause of this autoimmune disease is not known, little has been done in the way of finding out how to prevent it. There are possibly genetic, environmental and toxic factors involved. Saying that Degenerative Myelopathy is an autoimmune disease means the animal's immune system attacks its own cells; in this case, the central nervous system. The myelin insulation sheath around the nerves and axons (fibers) is gradually destroyed. It's worst in the thoraco-lumbar area of the spinal cord, but can also affect the brain stem and other nerve tissue.
Integrative or supportive treatment of German
Shepherd Dog Myelopathy, as promoted at the University of Florida vet school,
suggests the use of dietary alternatives and supplements to combat the
immune system, and is derived from an approach to treating Multiple Sclerosis.
You probably know at least one person with MS, and can recognize the similarity
in symptoms. Besides the vitamins E and C, the drugs, and the exercise
mentioned above, avoidance of toxins such as is found in pesticides and
lawn chemicals, and perhaps in some processed foods, is possibly helpful.
If you cannot manage "home cooking" with its involved recipes,
supplement dog food that is as natural as possible
with recommended aids. Soybean curd (tofu) protein contains flavonoids;
raw garlic (action is lost when is cooked or dried) is anti-bacterial and
anti-fungal, and may benefit the dog by reducing immune challenge.
Ginger is also anti-inflammatory and with garlic, can replace aspirin and
other NSAIDs. Adding soy concentrate, soy lecithin, and beta-carotene
and other vitamins to commercial food is recommended. Use "stress
formula" B-complex containing 100 mg of most of the B vitamin components;
or use yeast as a good source of these B-complex vitamins, trace minerals,
and some protein. It is relatively inexpensive; try half a tablespoon
mixed in each meal. If your dog gets flatulence from this, as most
do, use a discount or mail-order vitamin B complex pill instead.
Antioxidant vitamins E and C are synergistic; i.e., they work together better than they do separately. While dogs produce vitamin C, those with DM may need more than they can manufacture. In excess, it also can cause flatulence. I normally recommend not supplementing with vitamin C for longer than a month or two at a time, but in the case of a permanent, chronic disorder like DM, it's better to continue usage. Tolerance in the intestines may be for as much as 3000 mg per day, but up to 1000 mg twice a day should be enough unless it causes diarrhea. Selenium also is synergistic, helping vitamin E to be more effective. It can be toxic to medium-size dogs if given at more than 200 µg (micrograms) of selenium per day. I take 200 µg whenever I feel I'm not getting much western grain (good source of selenium) in my daily diet (which is rarely, such as when I’m out of the country for an extended time), and I weigh twice as much as my largest German Shepherd Dog.
Clemmons says that "Omega-3 fatty acids such as
EPA (eicosapentanoic acid) and DHA (docosahexanoic acid) are the constituents
of fish oils that act as anti-inflammatory agents and may be worth trying
if your dog has an autoimmune disorder or arthritis." Fortunate is
the owner who can give an afflicted dog a couple of cooked sardines or
a small piece of salmon as a daily, natural source of such fatty acids.
A 1000-mg fish oil capsule, tablespoon of ground flax seeds, or flaxseed
or wheat germ oil supplement can do about the same thing. If you
are really "into" the health-food store shopping, 500 mg twice a day of
GLA (gammalinolenic
acid), a fatty acid found in evening primrose
and black currant oils is an alternative anti-inflammatory without the
side effects of most anti-inflammatory drugs. All of the above should
be considered as optional adjuncts to conventional treatment with the drugs,
vitamins, and exercise, not replacements for them.
Disorders with similar symptoms: Cauda equina
syndrome, giant axonal neuropathy, and tumors may also mimic DM.
Many cases of spinal and related nerve damage are due to sudden trauma,
but some can result from encroachment of bone or tumors into the space
occupied by the cord. Since nervous tissue generally
does not regenerate, such conditions result in
partial or complete paralysis. Symptoms similar to myelopathy may be brought
on by a nerve cell degeneration normally associated with age. However,
with the latter disorder, the rapidly progressive nature of GSD myelopathy
is not seen. Neoplasms also cause the dog to display symptoms similar to
those of GSD myelopathy. These tumors on the spinal cord, neuroepitheliomas,
have a special predilection for German Shepherd Dogs from six months to
maturity at three years of age.
If you have lost a dog to this neurological disorder,
I offer my condolences in the form of a poem:
Rondeau on the Death of a Dog
They whimper in their darkness and their pain,
But oh, so softly that one has to strain
To hear. The life that Folly whispered low
Would stay (and how we wished that it were so!)
Ebbs out, although we grasp for it in vain.
Steady the flow, invisible the stain
Their life-blood leaves on those who here remain.
Unwilling to desert us as they go,
They whimper in their darkness.
We pity pets who painfully are slain,
Or even gently enter Death's domain,
But human-folk will feel Fate's cruelest blow,
For, long after they lay their friends below,
And sorrow weighs them down like iron chain,
They whimper in their darkness.
Fred Lanting ©, 1980
Fred Lanting, Canine Consulting. Seminars: Canine
HD & Other Orthopedic Disorders; Gait & Structure
(Analytical Approach); more. Guided tours of
Europe in connection with the Sieger Show and BSP, other dog
events
