Causes: As in acute form, parasites, gravid womb, insufficient ration,
overwork, exhaustive milking, chronic diseases. Symptoms: deranged
appetite, rumination, pica, eructations, regurgitations, tympanies,
colics after feeding, coated dung, diarrhœa, fever, hot clammy mouth,
sunken eyes, small weak pulse, palpitations, emaciation, weakness,
tender hypochondrium. Lesions: hypertrophy of gastric mucosa, granular
epithelium. Treatment: tonic regimen, diet, green food, roots,
sunshine, bismuth, salol, strychnia, pepsin, muriatic acid, common
salt, counter-irritants.
_Causes._ These are in the main the causes of the acute affection. There
may, however, be special persistent factors like parasites (strongylus
contortus and filicollis, spiroptera) in the stomach, the pressure of a
gravid womb, an alimentation deficient in lime or phosphorus, overwork,
exhausting milking, or chronic disease of important organs (heart,
liver, lung, kidney).
_Symptoms._ These are indefinite and not easily distinguished from those
of disorders of the third stomach. There is impaired or capricious
appetite, a disposition to eat lime, earth, and all sorts of
non-alimentary objects, rumination is rare or altogether suspended,
efforts to regurgitate are ineffectual, or result in gaseous eructations
only, there are tympanies and abdominal pains especially after feeding,
and constipation with a firm glazed appearance of any fæces passed, may
alternate for a short time with diarrhœa. The mouth is hot and clammy,
the eyes sunken and semi-closed, the pulse small and weak, though the
heart may palpitate, and there is a constantly progressive emaciation
and prostration. Among the more characteristic symptoms are tenderness
of the right hypochondrium to manipulation and percussion, and the
presence of slight hyperthermia.
_Lesions._ The changes consist mainly in hypertrophy of the gastric
mucosa, with changes in the epithelium and submucosa such as are already
described in the horse. The pyloric region suffers most, and here ulcers
are not at all uncommon.
_Treatment._ The main aim must be to remove the causes, and to build up
the general health, so that the patient may rise above the debilitating
conditions. More is to be expected from the change of diet to green
food, roots, mashes, etc., and an outdoor life than from the action of
medicines, which are liable to disappear by absorption in the first
three stomachs, so that they can only act on the fourth through the
system at large. Yet benefit may be expected from the use of nitrate of
bismuth, and salol, as calmatives and antiferments, nux vomica as a
tonic and even from pepsin and muriatic acid as digestive agents. The
two last are not dependent on the fourth stomach for their activity but
will digest the contents more or less in the first three, and the finely
disintegrated and partly peptonized ingesta coming to the fourth stomach
in a less irritating, and less fermentescible condition, lessens the
work demanded of that organ and gives a better opportunity for
recuperation. Small doses of common salt and one or other of the
carminative seeds may be added. The application of mustard or oil of
turpentine to the right hypochondrium will sometimes assist in giving a
better tone to the organ.