INFECTIOUS DISEASES. 91 



How is the diagnosis made ? 



Fever rising and falling, oedema, rapid emaciation even with 

 the good appetite, symptoms of anaemia and the finding of the 

 organism in the blood. 



What is the differential diagnosis? 



This disease may be mistaken for dourine, surra and mal de 

 caderas. 



Some investigators think that there is a possibility that the 

 four diseases are the same, while others claim there is a difference. 

 The lack of time for experimentation makes it difficult to draw 

 any specific conclusions but the following may aid somewhat. 



Dourine and mal de caderas cannot be transmitted to cattle; 

 where mal de caderas exists cattle do not die of surra. In surra 

 and nagana the same animals are attacked; the same course exists 

 in the horse whether surra or nagana. Cows seldom live with 

 nagana and rarely die of surra. Paralysis of the posterior extrem- 

 ity is an important symptom of mal de caderas. Dourine is 

 marked by the form of the organism and the mode of infection. 



What are the indications for treatment? 



There is no known treatment except the preventative treat- 

 ment given under surra. 



MAL DE CADEKAS. 



Define this disease. 



This is a specific infectious disease produced by the trypan- 

 osoma equinum and characterized by intermittent fever, ema- 

 ciation, progressive paralysis of the posterior extremity and death. 



What animals may be attacked? 



It is a disease of the horse, mule and hog. It is transmitted 

 to the dog, sheep, rabbit, rat and fowl. Cattle are said to be 

 immune. 



Insects are said to carry the organism producing the disease. 



What are the symptoms ? 



The temperature elevates slowly, then suddenly falls to normal. 



The animal is emaciated, oedema is usually present, the 

 urine is high colored and often contains blood. Paralysis of the 

 posterior parts which is progressive, interfering with the action of 

 the kidneys and bowels. 



The duration varies from two months to a year. 



