DISEASES OF THE HORSE. 549 



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

 be observed in the- jugulars, the breathing is quickened, and the indi- 

 vidual respirations shallow. On watching an animal in this condition 

 it may be noticed that it takes 7 to 8 ver}^ short inspirations, and these 

 are followed b}^ 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 swelling and 

 edema have increased considerabl}", and that on the under surface of 

 the ab.domen, where it was previously confined to the sheath, it has 

 now commenced to spread forward along the subcutaneous tissue 

 between the skin 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 suddenl}^ or gradually disappear, according to 

 the length of the fever period. These periods, alternating with and 

 without fever, may go on for 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 rapidlj'', but each 

 return of the fever brings with it, as a rule, an increase in the sever- 

 ity of the symptoms. There is increased ^^ellowness of the mem- 

 branes, 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 admixture of blood, and which on microscopic examina- 

 tion is found to contain a varying number 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 

 muscles 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 fre- 

 quentl}^ present paral3^sis of the sphincter ani and a dilated condition of 

 the anus. These symptoms taken together point 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 exu- 

 dation within 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 dis- 

 tance from the animal. In some of these cases the animal may sud- 

 denly drop dead; in others the emaciation and weakness become so 

 pronounced that the animal falls to the ground, and, after a short 

 struggle, succumbs to the disease. In other cases, again, the animal 



