SURRA. 551 



present a yellow tinge ; large ecchymoses, dark in color, appear on the 

 conjunctival membranes, the action of the heart is irritable, the pulse 

 full and quick, or at times intermittent, and regurgitation may be 

 observed in the jugulars, the breathing is quickened, and the individ- 

 ual respirations are shallow. On watching an animal in this condi- 

 tion it may be noticed that it takes T to 8 very short inspirations, and 

 these are followed by a much more prolonged and sonorous one ; at the 

 same time the breathing is more abdominal than thoracic in character. 

 On examination, of the legs it will be found that the sw^elling and 

 edema have increased considerably, and that on the under surface of 

 the abdomen, where it was previously confined to the sheath, it has 

 now cammeneed to spread forward along the subcutaneous tissue 

 between the slrin and the muscles. During the whole of this time the 

 appetite will have varied little, and the evacuations will be only 

 slightly, if at all, altered in character. In the blood a repetition of 

 the previous events takes place, the parasites make their appearance 

 and increase to a maximum and again suddenly or gradually disap- 

 pear, according to the length of the fever period. These periods, 

 alternating with and without fever, ma}^ go on far a considerable time. 

 The progress of the disease is variable and greatly depends upon the 

 condition of the animal attacked, the weak one succumbing very rap- 

 idly, but each return of the fever brings with it, as a rule, an increase 

 in the severity of the symptoms. There is increased yellowness of the 

 membranes, fresh crops of petechias on the conjunctiva, a collection of 

 gelatinous material at the inner angle, which at times becomes red in 

 color from an admixtuFe of blood, and which on microscopic exami- 

 nation is found to contain a varying nimiber of the surra parasites ; 

 increased swelling and edema of the extremities and abdomen, which 

 now extends between the fore limbs and up the chest. During this 

 time the wasting has been steadily progressive, especially of the mus- 

 cles of the back and those surrounding the hip joint and the glutei. 

 Toward the termination of the disease it will be noticed that an 

 animal is disinclined to move, and when made to do so there will be 

 manifest loss of power over the hind quarters, somewhat simulating 

 a slight partial paralysis, and the hind quarters of the animal reel 

 from side to side. In connection with this it may be noted that there 

 is frequentlj^ present paralysis of the sphincter ani and a dilated 

 condition of the anus. These symptoms taken together jwint to some 

 interference with the normal functions of the spinal cord in the lower 

 dorsal and lumbar regions, and are probably due to pressure caused 

 by an exudation wdthin the spinal membranes. In many cases shortly 

 before death the heart's action becomes exceedingly violent, shaking 

 the whole frame at each beat, so that the sound can be heard at some 

 distance from the animal. In some of these cases the animal may 

 suddenly drap dead ; in others the emaciation and weakness become 



