INFLUENZA. 501 



chills of the flanks, the muscles of the croup, and the muscles of the 

 shoulders, or of the entire body, lasting from fifteen to thirty min- 

 utes, and frequently a grinding of the teeth which warns one that a 

 severe attack may be expected. The hairs become dry and rough and 

 stand on end. The body temperature increases to 101°, 104.5°, and 

 105° F., or even in severe cases to 107° F., within the first twelve or 

 eighteen hours. The horse becomes stupid, stands immobile w^ith its 

 head hanging, the ears listless, and it pays but little attention to the 

 surrounding attendants or the crack of a whip. The stupor becomes 

 rapidly more marked, the eyes become puffy and swollen with ex- 

 cessive lachrymation, so that the tears run from the internal canthus 

 of the eye over the cheeks and may blister the skin in its course. The 

 respiration becomes accelerated to twenty-five or thirty in a minute, 

 and the pulse is quickened to seventy, eighty, or even one hundred, 

 moderate in volume and in force. There is great depression of mus- 

 cular force ; the animal stands limp, as if excessively fatigued. There 

 is diminution, or in some cases total loss, of sensibility of the skin, 

 so that it may be pricked or handled without attracting the attention 

 of the animal. On movement, the horse staggers and show^s a want of 

 coordination of all of the muscles of its limbs. The senses of hearing, 

 sight, and taste are diminished, if not entirely abolished. The visible 

 mucous membranes (as the conjunctiva), from which it is known as 

 the pinkeye, and the mouth and the natural openings become of a 

 deep saffron, ocher, or violet-red color. This latter is especially 

 noticeable on the rim of the gums and is a condition not found in any 

 other disease, so that it is an almost diagnostic symptom. In some 

 outbreaks there is much more swelling of the lids and weeping from 

 the eyes than in others. If the animal is bled at this period the blood 

 is found more coagulable than normal, but at a later period it be- 

 comes of a dark color and less coaguliible. There is great diminution 

 or total loss of appetite with an excessive thirst, but in many cases 

 in cold-blooded horses the animal may retain a certain amount of 

 appetite, eating slowly at its hay, oats, or other feed. There is some 

 irritation of the mucous membrane of the respiratory tract as shown 

 by discharge of mucus from the nose, and by cough. Pregnant mares 

 are apt to abort. 



We have, following the fever, a tumefaction, or edema, of the sub- 

 cutaneous tissues at the fetlocks, of the under surface of the belly, and 

 of the sheath of the penis, which may be excessive. The infiltration 

 is noninflammatory in character and produces an insensibility of the 

 skin like the excessive stocking which we see in debilitated animals 

 after exposure to cold. In ordinary cases the temperature has reached 

 its maximum of 105° or 106° F. in from twenty-four to forty-eight 

 hours from the origin of the fever. It remains stationary for a period 

 of from three to four days without so much variation between morn- 



