404 SURRA 



The respective duration of the paroxysms and intermis- 

 sions is very irregular. Lingard puts it down as from one to 

 six days. He states that in a few experimental horses the 

 paroxysms lasted from eighteen to twenty-two days. 



The duration of the disease is, according to Gunn, about 

 fifty-two days. In the Philippine Islands the duration in 

 horses is from fourteen days to three months. The prognosis 

 is always unfavorable, the mortality in most species of animals 

 being 100 per cent. In cattle a variable percentage recover. 



§ 315. Morbid anatomy. As a rule there is great 

 emaciation, enlargement of the liver and spleen, petechiae on 

 various internal organs. A yellow or amber-colored jelly-like 

 exudation occurs in the connective tissue of the throat, chest 

 and abdomen, about the muscles and other tissues, and espec- 

 ially around the base of the heart. The lungs often show 

 signs of inflammation. The mucous membranes and other 

 tissues are frequently tinged yellow by the coloring matter of 

 the bile. 



It has been stated that the hide is often removed with 

 difficulty. In the areas corresponding to the edema dur- 

 ing life are found yellowish-tinged, gelatinous infiltrations. 

 The serous membranes, especially the peritoneum and pleura, 

 often show flakes of plastic, fibrous material. These are es- 

 pecially numerous over the liver. All of the organs have a 

 dry, pale appearance. There are numerous sub-serous hemor- 

 rhages, particularly on the right side of the heart and over the 

 lower portion of the lungs. The lymphatics are in general 

 somewhat enlarged, often markedly so. The heart muscle 

 shows parenchymatous changes, in degree depending some- 

 what on the duration of the disease. 



In some of the lower animals the scrotum and even the 

 testicles in the male and the vulva in the female are greatly 

 swollen, and in the male rabbit the tension may be .so great as 

 to rupture the scrotum. Small preputial or labial ulcers are 

 not uncommon. 



Steel noticed ulceration of the stomach in about two-thirds 



