The lesions are ill-recognised. The animals die rapidly, and if not immediately examined show no characteristic lesions. The changes to be looked for consist in intense congestion or ulceration of the intestine, or even in ulceration of arterioles and of arteries of considerable size.
In parasitic enteritis one finds localised inflammation and, in the epithelial interstices, sporozoa, which cause the rupture of blood-vessels.
Treatment. It is necessary to act energetically from the outset, and to arrest hæmorrhage by acting on the intestine, on the vascular system, and on the skin. Mustard plasters or other external stimulant applications are therefore indicated. Internally, small doses of astringents like tannin, preparations of opium, 25 per cent. solution of sulphuric acid in alcohol, etc., are given to produce constriction of the vessels, though they seldom arrest the discharge of blood for long. In most cases it is necessary to have recourse to subcutaneous injections of ergotine, in doses of 5 to 10 grains in young animals, and 15 to 45 grains in adults. The dose may be given in two parts to prevent an unduly severe action. The smooth fibres of the small vessels are thus directly excited, and hæmorrhage ceases in consequence of clotting in the contracted vessels.
One may give for the same purpose injections of arseniate of strychnine, which has the advantage of sustaining the tone of the heart and preventing syncope. The dose should not exceed 1·5 grains in large animals.
Finally, a stimulating diet containing milk, alcohol, soup, cooked vegetables, and small quantities of vegetable pulp is useful.
With early treatment animals sometimes recover in a few hours.
Intravenous or subcutaneous injections of physiological salt solution (2 drachms of sodium chloride in one quart of water) may prove of value when hæmorrhage has been abundant and vascular pressure is low.
CHRONIC ENTERITIS (CHRONIC DIARRHŒA).
Chronic diarrhœa is common in byres. It appears suddenly, often fails to attract attention, and assumes the form of simple diarrhœa, a fact which accounts for it frequently being described as chronic diarrhœa, dysentery, etc.
Causation and pathogeny. This form of diarrhœa occurs sporadically throughout France, and under exceptional circumstances may permanently attack a number of animals in a given place.