At night, the animal seems to have an increase of fever, sometimes of a remittent type, after which he becomes drowsy and lies down to rest himself or to sleep, if he can; but the difficulty of breathing, the abdominal pains, soon force him to rise again, which he cannot do without an effort.
4. _Period of Decline and Sinking._--This stage is observed to extend from the eighth day to the twelfth or the fourteenth. The morbid functions pursue their course, for the disease has its regular phases and a successive variation of phenomena. The secretions, which a few days before were fluid and irritating, have undergone a change; they have become thick and purulent, they flow more slowly from the ocular mucous membranes, and also from the nasal and buccal, which are red and inflamed, and they already emit a foetid smell. The dull tarnished eyes become hollowed, purulent mucus lodges within their orbits, the bronchiæ are stopped up, the breathing grows louder and more panting, the animal instinctively stretches his neck to ease it; the wasting of the flesh exposes the bones of the sacrum and coccyx, laying bare the vertebræ and the ribs; the emphysematous tumours are more extensive and crackling; the skin, less heated, wrinkles up and splits about the bony protuberances; the udders are crusty and excoriated; detached boils, hard and rounded at first, then soft and purulent, begin to show themselves on the trunk and the upper parts of the limbs. The diarrhoea, still frequent, becomes bloody and intolerably offensive.
At this final period the organic structure yields to the effects of a general alteration of the liquids and solids. The vital force has lost the power of reaction; a mass of blood, decomposed by the double influence of a virulent toxæmia and the obstructions of respiration, conveys to all the organs a principle of dissolution; the nervous system is in a manner paralysed, as is shown in the animal's insensibility.
The secretions stop up the various channels and cavities; they lodge within them; they undergo a putrid decomposition, and pass out with difficulty in the form of a purulent and bloody flux, in the highest degree infectious. Very soon the sick animal has ceased really to live; it struggles and labours with its agony; if the lungs are clogged with gas or fluid they rattle hurriedly and often; the animal cannot hold its head up even when lying down, and when standing moves it to and fro as if affected with the natural shaking of old age, and as if seeking to ward off some indescribable evil, the occurrence of which it was awaiting.