SUKRA. 413 



Owing to the somewhat curved and twisted shape of the 

 parasite, and the curling of the flagellum, in the stained pre- 

 parations it was difficult to make exact measurements, but I 

 was able to ascertain that the average widtli, according to 

 whether ihe membrane was visible or not, varied from 1 to 

 2 mm., and the length of the body from 20 to 30 mm. The 

 flagellum was about the same length as the body. 



Smiilar if not identical parasites are found in the blood of 

 rats, bandicoot, mudfish, carp, and apparently inducing no 

 inconvenience to their hosts. I cannot, however, agree with 

 Crookshank that the parasites in surra are only associated with 

 the disease, the impoverished blood affording a suitable nidus 

 for their development, while the contaminated water may be 

 the common source of the organism and the disease. 



It was discovered by Lingard that one attack did not render 

 an animal immune to a second, and the following experiment is 

 interesting as bearing on this point. Twelve months after an 

 Australian horse had been cured of surra by the administration 

 of arsenic, iodide of arsenic, and mercury, this horse was 

 inoculated with a minute drop of surra blood — a mere trace 

 of soiled blood being smeared over a scratch on the muzzle — 

 in order to ascertain whether any immunity had been given by 

 the previous attack. The latent period of the second attack 

 occupied seven days. The progress of the disease was marked 

 as usual by paroxysms of fever and intermissions, the former 

 occupying a much more prolonged period — twenty-two days — 

 and the latter being shorter than usual — only two days. 



Death took place on the fifty-third day of the disease, clearly 

 proving that one attack of surra is unable to protect against 

 a second attack. — (Lingard, Report on Surra to the Insijedor- 

 Gcncral, Civil Veterinary Department, Simla, 1895.) 



Symptoms of Surra. — Outbreaks of this disease occur in India 

 and Burmah chiefly after the rainy season. The more prominent 

 symptoms observed at first are a capricious appetite, dulness, and 

 slight fever, which after a few days' rest frequently pass off 

 without medical treatment. When a relapse occurs, which is 

 almost invariable, there is an increase of fever, the mucous 

 membranes are yellow in colour, and petechice become apparent, 

 also local or general urticaria. There is generally some oedema 

 of the limbs, also beneath the belly, chest, and sheath. The 



