400 SURRA 



SURRA 



Synonyins. Relapsing fever of equines; pernicious ane- 

 mia of horses. 



§ 309. Characterization. Surra is an infectious dis- 

 ease of solipeds and camels caused by a flagellate protozoan. It 

 is determined by a continuous fever with alternate paroxysms 

 and intermis.sions, with a general or localized eruption of the 

 skin, petechiae of the mucosae and more or less subcutaneous 

 edema. There is rapid emaciation and great weakness. It is 

 usually fatal. It attacks horses, asses, mules, cattle, goats, 

 dogs, and rats. It can be inoculated into other animals such 

 as rabbits, guinea pigs and mice. From an economic point of 

 view it is reported to be essentially a disease of horses. 



In India cattle are said to be infected with the trypan- 

 osoma of surra but they are not appreciably affected by them. 

 It is reported that horses become infected by insects that have 

 iirst bitten such cattle. 



§ 310. History. This disease appears to have been 

 known for many years to the natives of the low lands on both 

 sides of the Indus on the northwest frontier of India. Haig 

 appears to have observed it in Persia in 1876. In 1880, Evans 

 found several cases of it in the Dera Ismael Khan county. He 

 was the first to describe it and attribute its cause to an animal 

 parasite which he discovered in the blood. In 1885, Steel met 

 with a disease among mules in Burma which he regarded as 

 identical with Evans' surra, and which he believed to be re- 

 lapsing fever. In 1888 there was an outbreak among the 

 Bombay Tramway Company's horses. Since then surra has 

 become epizootic in Bombay; Lingard reports that thousands 

 of ponies, horses, camels and asses died from it during the 

 rains of 1893 and 1894. Its ravages in the Punjab and North- 

 west Provinces during 1895 are reported to be appalling. 



§ 311. Geographical distribution. It is a disease of 

 Asia and Africa. It is reported that " the distribution of this 

 malady seems to be entirely influenced by the physical aspect 



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