Causes: As in acute: troubles of circulation, heart, lungs, verminous
embolism, parasitism, skin disease. Lesions: thickening of mucosa,
pigmentation, rigidity, hypertrophy of villi, follicles and glands,
ulceration, polypi. Symptoms: impaired appetite, buccal fœtor,
retracted flank, unthrifty skin, pallid mucosæ, colics, tympanies,
rumblings, irregular bowels, emaciation, perspiration, fatigue.
Treatment: dietetic, tonic, bitters, salines, aromatics, enemata,
bismuth, laudanum, calomel and chalk, iron, astringents,
counter-irritants, electricity, sunshine.
_Causes._ This may occur from a continuance of the same causes as in the
acute, or from an imperfect recovery from the acute form. It may result
from troubles in the circulation, as valvular disease of the heart, or
emphysema of the lungs, which forces the blood back on the venous
system, including the liver and portal vein. Or the lesions that come
from verminous embolism may leave such alteration in the intestinal
walls as entail chronic congestion of the mucosa, or intestinal
parasites may be the cause. Severe and inveterate skin diseases appear
to affect the intestinal mucosa by sympathy, just as diseases of that
mucosa usually entail skin diseases.
_Lesions._ Attenuation of the coats of the small intestine and
thickening of the mucosa of the large have been noticed. The mucosa is
darkly pigmented and covered with excess of mucus. The thickening of the
mucosa may extend into the submucous tissue, giving a firm leathery
feeling to the part, and entailing a loss of elasticity. The villi are
hypertrophied and the follicles of Lieberkuhn and Peyers’ patches may be
congested, ulcerated or otherwise altered. Polypoid growths are not
uncommon on the mucosa, and the mesenteric glands are enlarged and
pigmented.
_Symptoms_ are by no means very definite. Disturbance of the digestive
functions, capricious or impaired appetite, dry fœtid mouth, tucked up
abdomen, dry hair and skin, pallor of the visible mucous membranes,
slight intermittent colics and tympanies, loud rumblings in the bowels,
and relaxed bowels, or alternate costiveness and diarrhœa, with some
tenderness on manipulation of the abdomen are the usual symptoms. The
animal loses flesh, has dry, unthrifty coat, and sweats and is easily
exhausted at work.
_Treatment._ Dietary care is the first essential. Boiled oats, barley,
rye or bran, in small amount and flaxseed tea may indicate the kind.
These should be given in small amount often, and at regular intervals.
A failing appetite may be stimulated by nux vomica (10 grains) twice
daily, or by gentian or other bitter, along with common salt and
aromatics.
Constipation may be combated by fresh green food in small quantities, or
by an ounce each of Glauber salt and common salt given every morning
before feeding, in a drink of water (half to a bucket, if possible), and
10 to 20 grains of nux vomica may be advantageously added. Soapy
injections with salt or glycerine may also be given.
Diarrhœa may be moderated or checked by nitrate of bismuth (2 drachms),
with laudanum (1 ounce), repeated as may be demanded. A combination of
calomel and chalk (1:12) will often serve a good purpose in drachm doses
several times a day. For persistent diarrhœa Cadeac recommends the
following: Iron carbonate 4 drachms, lime water 10 ounces, alum 1
drachm, powdered oak bark 1 ounce, given in water and farina.
Sepsis and fermentation must be combated by the same means as in the
acute type, and the same counter-irritants may be resorted to. A life in
the open air or sunshine, but without undue exertion is of great
importance.