Etiology, Anatomical Changes, Symptoms. 813 



(Leese) in the bodies of the flies, which latter aie infectious only the first day 

 after sucking the blood. 



The question as to the mode and nature of natural infection cannot yet be 

 considered as solved, and only recently Holmes, among others, expressed himself 

 negatively on the exclusive transmission by horse flies, pointing out that the disease 

 rages sometimes in the months from October to December inclusively, whereas the 

 flies usually fly only in the months of June to August. 



Anatomical Changes. Besides marked emaciation and 

 changes indicating anemia and cachexia, a yellow, gelatinous 

 infiltration of the subcutis is present in different regions of 

 the body, also small hemorrhages in the serous and mucous 

 membranes, serous exudates in the pericardium and in the ab- 

 dominal cavity, more or less pronounced acute swelling of the 

 spleen (especially in acute cases), and swelling of the lymph 

 glands ; in some cases superficial ulcerations also appear on the 

 tongue and on the gastric mucous membrane. 



Symptoms. These resemble in general those of nagana. 

 In solipeds, which are the most susceptible animals to natural 

 infection, the disease commences after an incubation of 4 to 1.3 

 days (Lingard) with fever (rise of temperature up to 40.5-41°), 

 great languor and weakness, whereupon petechiae soon develop 

 on the mucous membranes, especially on the conjunctiva. 

 Urticaria-like eruptions appear on the skin, and edematous 

 swellings on the extremities, the genital organs, in the sub- 

 maxillary region, and on the lower abdomen. 



A fatal termination may result even in the first days of 

 the disease, usually however a marked improvement sets in 

 after several days, but the febrile attack returns after a short 

 time. The febrile stages usually last for four days, and alter- 

 nate with fever-free periods lasting for several days, whereby 

 the animals become more and more weakened, the paleness, 

 and later also the icteric discoloration of the mucous naembranes 

 becomes more pronounced, the superficial lymph glands swell, 

 the respiration becomes accelerated and labored, the pulse fre- 

 quent and small. In spite of good appetite the animals become 

 greatly emaciated, their gait is staggering, finally they lose 

 the use of their hind parts and die with symptoms of severe 

 dyspnea. 



Of other symptoms there may be observed hemorrhages 

 in the anterior chamber of the eye, diffuse keratitis, petechiae 

 in the mucous membrane of the vagina, albuminuria during the 

 febrile attacks, continuous erection of the penis (formation 

 of thrombi in the corpus cavernosum?), etc. 



Trypanosomes are found in the blood especially at the be- 

 ginning of the febrile attacks, otherwise their number fluctuates 

 in the course of the disease within wide limits. 



The course extends usually from 1 to 2 months, more rarely 

 from 1 to 2 weeks, or on the contrary for 3 to 4 months, the 

 febrile attacks becoming gradually weaker in the later stages. 



