Symptoms. 41 



attracts little or no attention. The cough is usually 

 small, weak, short and husky, but somewhat painful and 

 attended by some arching of the back, an extension of 

 the head upon the neck, and protrusion of the tongue. 

 This many continue for weeks without any noticeable de- 

 yiation from the natural temperature, pulse or breathing, 

 and without any impairment of appetite, rumination or 

 coat. The lungs are as resonant to percussion as in 

 health, and auscultation detects slight changes only, 

 perhaps an unduly loud blowing sound behind the middle 

 of the shoulder, or more commonly an occasional slight 

 mucous rattle, or a transient wheeze. In some cases the 

 disease never advances further, and its true nature is to 

 be recognized only by the facts that it shows itself in an 

 infected herd or on infected premises, and that the victim 

 proves dangerously infecting, to healthy animals in unin- 

 fected localities. It may be likened to those mild cases 

 of scarlatina which are represented by sore-throat only, 

 or to the modified variola, known as chicken-pox. 



In the majority of cases, however, the disease advances 

 a step further. The animal becomes somewhat dull, more 

 sluggish than natural, does not keep constantly with the 

 lierd, but may be found lying alone ; eats and ruminates 

 more tardily and less frequently ; breathes more quickly 

 (20 to 30 times per minute in place of 10 to 15) ; retracts 

 the margins of the nostrils more than formerly ; the hair, 

 especially along the neck, shoulders and back, stands 

 erect and dry ; the muzzle has intervals of dryness, and 

 the milk is diminished. The eye loses somewhat of its 

 ]n-ominence and lustre, the eyelids and ears droop slightly, 

 and the roots of the horns and ears and the limbs are 

 hot or alternately hot and cold. By this time the tem- 

 perature is usually raised from 103 degrees, Fahrenheit, 

 in the slightest or most tardy cases to 105 degrees and 

 upward to 108 degrees in the more acute and severe. 

 Auscultation and percussion also now reveal decided 

 changes in the lung tissue. 



