Causes: distemper, in long-haired pets, pyæmia, exposure to cold,
violent overexertion, traumas, vertebral caries or abscess. Lesions:
in lumbar enlargement, horns yellowish, red, friable, pultaceous,
leucocytes in excess, punctiform extravasations, neurons opaque;
granular, filaments diffluent, varicose, sclerosis. Meninges
congested, thickened. Symptoms: as in horse, extreme hyperæsthesia,
later anæsthesia, tremors or twitching, later paraplegia. Treatment:
Laxatives, ice bags, sedatives, later derivatives, cauterization.
During convalescence, phosphates, iron, zinc, strychnia. Attend to
bladder and rectum, light, laxative diet, pure air and water.
_Causes._ This disease is a common result of distemper and according to
Trasbot, is much more frequent in long-haired and pet dogs than in the
short-haired and mongrels. The shelter of the hair, like the warm indoor
atmosphere, seems to contribute to a special sensitiveness of the
cutaneous and nervous tissues. The infective inflammation of the myel is
also seen in pyæmia, rabies and milk sickness. It appears to be further
induced by exposure to cold draughts when heated, or excited, by
plunging into ice cold water, by lying on cold, damp, stone pavement or
metallic plates. Violent overexertion, excessive fatigue, and a variety
of traumatisms are further factors. Kicks, blows on the back, concussion
from falling from a window or other height, and sprains received in
fighting or otherwise, are common causes. Disease of the vertebræ or
abscesses in their vicinity will sometimes extend to the meninges and
cord.
_Lesions._ These are like those in the larger animals, being to a large
extent determined by the cause and nature of the lesion, concussion,
sprain, fracture, pyæmic, septicæmic, or other infection. The
implication of the myel to the exclusion of the meninges is very
frequent and the lumbar enlargement is the most common seat of disease.
Localization in the brachial enlargement or in one lateral half of the
cord is uncommon. The gray matter towards the extremity of the horn is
the most commonly involved, reflecting a yellowish, grayish red or deep
red color, and breaking down into a pultaceous mass on the slightest
pressure. At an advanced stage the altered coloring matter gives to the
tissue a brownish yellow color without altering its consistency. The
still vital and vascular area around the centre of softening may be
slightly swollen and abnormally firm. The neuroglia is the seat of
leucocytosis, and minute (usually punctiform) extravasations of blood.
The red globules are crenated or otherwise distorted and the white are
granular and opaque. The neurons are swollen, granular and opaque and
the nerve fibres are more or less diffluent, moniliform and in their
substance show no clear outline of white substance and axis cylinder.
Interruptions by granule masses and vacuoles are common. In old standing
or chronic cases the liquid exudate and granular debris have been
largely absorbed and the thickening of the neuroglia by fibrous
neoplasm, has restored the firmness or even approximated the part to a
condition of sclerosis.
In case the meninges are involved there is thickening by exudation into
their substance or on their surface, there may be adhesion between the
outer and inner layers of the arachnoid and a serous fluid, red, milky
or clear, distends the arachnoid or subarachnoid space. The false
membranes, here as elsewhere, are usually red if recent, and increase in
pallor with age.
_Symptoms._ These are in the main the same as in the larger animals. The
early excitement usually takes the form of hyperæsthesia. When lifted,
pressed, touched or only approached the dog may growl, howl, snap,
cringe, cower or tremble, glancing up meanwhile with anxious or pleading
eyes. When later, this gives place to anæsthesia no such interference
will draw a response. The motor disorders at the outset are mostly of
the nature of tremors or twitching of the muscles of the limbs or of
those parts of the trunk corresponding to the seat of the lesion. In
exceptional cases spasms or convulsions may be shown. Trasbot records a
case of very acute myelitis of the brachial enlargement in which there
were clonic contractions of the muscles of the neck, jaws and eyeballs,
and grinding of the teeth, which condition lasted for thirty-six hours.
When this motor excitement merges into paralysis it usually attacks the
hind limbs which are extended backward helpless while the animal pulls
himself forward by his fore limbs. Some such cases are restless and in
continual movement while others are dull, apathetic and indisposed to
move. The precise seat of the paresis or paralysis will be determined by
the seat of the lesion as in the larger animals. Thus paraplegia is most
common, less frequently hemiplegia, palsy of the fore limb, palsy of a
single limb, and monoplegias, about in the order named. Palsy of the
tail and sphincters implies a lesion of the lumbar section of the cord
and is very offensive in the incontinence of urine and fæces especially
in long-haired subjects.
_Treatment._ The abstraction of blood is rarely called for in myelitis
in the dog. If admissible at all it is in the case of strong, vigorous,
plethoric animals which have been attacked in connection with sudden
exposure to cold or accidental concussion, and which are presented for
treatment at once. Then leeches may be applied to the abdomen or inside
of the thigh, or the jugular may be opened with a lancet. Usually on the
other hand the patient is fat, lymphatic, and, if a few days have
elapsed, even anæmic, while if he has been the victim of an accident the
shock and prostration would forbid any depressive measures.
Derivation toward the bowels may be sought by purgative doses of calomel
or jalap. In case of high fever, cold may be applied (in the form of
icebags, evaporating lotions or wet cloths) to the tender portion of the
spine. If the attack has followed exposure to cold, salicylate of soda
may be given, otherwise the bromide of potassium or camphor. Acetanilid
and other antithermic agents may be used with caution.
With the abatement of the high fever and the supervention of paresis, if
not before, counter-irritants are demanded.
Owing to the propensity to lick and the danger of absorption, poisonous
agents are virtually proscribed. Yet Möller advises cantharides, croton
oil, mercuric iodide, and oil of mustard, and Trasbot restricts the
choice to tartar emetic one part to sixteen parts of lard. This the
latter rubs softly along the spine for several minutes. If the dog is
closely watched or muzzled this or the mustard or croton oil may be
admissible. If otherwise, a long-haired dog may be rubbed on the spine
with a combination in equal parts of strong aqua ammonia and olive oil;
or it may have applied for some minutes wet cloths rather hotter than
the hands can bear; or a light cauterization may be made with a Paquelin
cautery. At this stage, too, bitters and phosphate of lime may be given.
Trasbot has long used with the best results 1 grain doses of neutral,
gelatinoid phosphate of lime, repeated two or three times a day. Iron
may also be resorted to, or sulphate of zinc. Strychnia and electricity
are also of great value as soon as the irritability of the spinal
centres will allow of their safe employment. Massage and gentle exercise
are important.
From the first, attention must be given to obviate the retention of
urine and fæces, and the strict antisepsis or asepsis of the catheter
adopted to prevent infective cystitis and nephritis.
Throughout the disease abundant nourishment of an easily digestible
quality is demanded. Cleanliness, pure air and general comfort must not
be forgotten.