Fleshy neck, thick mane and tail, lymphatic constitution, profuse
perspiration, lack of cleanliness, alkaline soaps, plethora, foul
stable, pus microbes. Symptoms: itching or tenderness, shedding hair,
thinning of mane and tail, skin thickened, ridges and folds,
tenderness, moisture, crusts raise hairs from follicles, fœtor, sores
and ulcers, matted hairs. Treatment: remove general and local causes,
cleanse, cool, pure stable, clip, reduce grain; cooling, laxative
food, soothing or stimulating applications, zinc oxide, talc, olive
oil and diachylon plaster, iodoform, silver nitrate, oil of cade, or
of white birch, sulphur iodide, Canada balsam and sulphur, green soap,
dusting powders, ointments.
This condition is especially common in horses with a profusion of long
hairs in the mane and tail, and in the heavy draught animal with a
thick, fleshy neck. In such the skin is very sensitive, and when profuse
perspiration soaks the skin, or concretes and decomposes about the roots
of the hairs, the local irritation necessary to the production of the
eruption is present. A lack of careful grooming is therefore a common
cause, yet soap left in washing the mane or tail may be no less
injurious. Plethora has its influence in many cases, and the ammoniacal
fumes from a wooden stable saturated with excretions are not to be
ignored. Finally in cases accompanied by pustular eruption, the pus
microbes must be recognized as factors.
_Symptoms._ There may be marked itching or extreme tenderness of the
part affected or in the absence of both there may occur a gradual
shedding of the long hairs, so that an increasing thinness of the mane
and tail (rat tail) becomes apparent. The skin covering the affected
parts is thickened, inflamed and thrown into ridges and folds, one
rubbing against another. The surface feels moist or is covered by crusts
formed by the condensation of the moist exudate, and embracing the hairs
and drawing them out of their follicles. Beneath the concretions the
skin is soaked in the tenacious fœtid liquid discharge. The hair
follicles become atrophied in connection with the evulsion of the hairs,
or under congestion the hairs stand rigidly erect, and bristly or curly.
As the freer secretion abates, the exudate become more purely scally or
encrusted, but the skin remains thickened and thrown into folds. Under
the inveterate rubbing or gnawing the skin is often extensively abraded
and large open sores are formed which are indolent and slow to heal.
That matting together of the hairs which has been known as _plica
Polonica_ is often the result of the disease of the hair follicles and
the accumulation of scabs which takes place in this disease, rather than
to a special infection like gregarina (coccidiosis).
_Treatment._ The first consideration must be to remove all general and
local causes of eczema, insure perfect cleanliness and good grooming in
any case in which these may been lacking, purify the air of the stable
if that has been foul, procure a cool environment when that has been too
hot, clip the patient if habitually soaked with perspiration by reason
of a heavy coat, suspend or moderate the work if that has been too
exacting, withhold a heating grain ration (corn, buckwheat, barley,
wheat, peas, beans), and furnish cooling, laxative, easily digested
food. In the cases before us the acute, irritable stage has usually
passed, so that the more stimulating applications may be safely used,
yet in many old standing cases a fresh eruption may have taken place,
which would demand for a time the most soothing applications only. Apart
from such cases the more stimulating dressings are applied at once.
The affected surface is exposed by clipping or shaving off the long
hairs, thus at once removing a source of heat and irritation and
allowing of the direct and thorough application of the dressing. Among
the astringent and stimulant applications oxide of zinc ointment and
benzoated oxide of zinc are among the simplest and least likely to
irritate, but the stronger applications can usually be borne. The Lassar
paste consists of two parts each of finely powdered talc and zinc oxide,
four parts of vaseline and three per cent. of salicylic acid. Oxide of
bismuth may substitute the zinc oxide. Three parts of olive oil and four
of diachylon plaster melted together and stirred until cool, makes
another mildly astringent and sedative application. Iodoform 1 dr. to an
ounce of vaseline is an excellent agent. A mixture of iodoform and
tannin is used as a dusting powder by Friedberger and Fröhner: or silver
nitrate solution (6:100) may be used. Tar ointment (1:8) with a little
subcarbonate of potassium added makes an excellent application. Oil of
cade and oil of white birch may be used in the same way, the latter
being the most desirable as a rule. Ammonia chloride of mercury as an
ointment (1:10), often acts well and the black wash, formed by the
decomposition of calomel with potash is often serviceable. Iodide of
sulphur and vaseline (1:10) is often an excellent resort. An ointment of
equal parts of Canada balsam and sulphur or iodide of sulphur in four
parts of vaseline is often effective. Other valuable preparations are
ointments (10%) of ichthyol, naphthol, chrysarobin or pyrogallol.
Hebra’s _last resort_ of green soap is never to be forgotten, the
affected skin being thickly smeared with the soap which is left to dry
on, and is repeated and rubbed in, for several days in succession. It
may seem at first to aggravate the disease by reason of the solution and
removal of the covering of the vesicles or pustules and the exposure of
a pink sensitive surface, but day by day this improves and the skin
becomes smooth and more natural. After a few days of this treatment, it
may, if necessary, be followed by astringent or stimulant dressings, or
the varied medicaments may be incorporated with the soap so as to form
one dressing to be applied from the first. When a healthy action has
been once established, all that is required further may be cleanliness,
with the use of bland dusting powders or ointments to establish the
cure.