42^! DISEASES OF THE BLOOD. 



natural prairie, but do not develop in parts artificially sown with grass 

 such as lucerne, and that when contaminated or diseased animals are 

 transferred to artificial meadows they do not convey the disease to 

 other animals already there ; the latter are proof against it. 



Diagnosis. The disease is so typical that it cannot be mistaken for 

 anthrax. In anthrax the urine is never htemoglobinuric and very rarely 

 hffimaturic, and the faeces are sometimes blood-stained, a symptom never 

 present in piroplasmosis. Anthrax can be transmitted to experimental 

 animals, but piroplasmosis cannot. 



Prognosis. The prognosis is generally grave. 



Treatment. Van Hellens recommends the use of quinine in large 

 doses. He give 5 drachms in one dose, and repeats it for the next two, 

 three, or four days. 



Lignieres says that he has never obtained the slightest success 

 with quinine, though it is true he has never given higher doses than 

 2 J drachms. 



Attempts have been made to confer immunity by injecting animals 

 with serum from others which have recovered. Vaccination with the 

 blood of patients arrived at the period of convalescence has also been 

 tried. The results, however, have not been very satisfactory. 



Lignieres has formulated an efficient method of vaccination, of which 

 he has not yet published the full details, but which appeared by reason 

 of its simplicity likely to render great service. Nevertheless, his most 

 recent reports seem to show that vaccination is not always efficacious, 

 and that in the Argentine Eepublic alone several varieties of the disease 

 exist, two being caused by allied but difl'erent parasites. The vaccine 

 used against one variety is jJowerless against the other. The problem of 

 vaccination would therefore a^^pear to be much more complex than in 

 the case where one form only occurs in any particular country. 



The immunity arising from attacks of piroplasmosis is in direct ratio 

 to the gravity of the disease, and according to Lignieres' views this 

 acquired immunity is due to the secretion by the piroplasma of a sub- 

 stance which is toxic for the red blood corpuscles. This toxic substance 

 provokes, as in other diseases, an organic antitoxic reaction. 



BOVINE PIROPLASMOSIS IN FRANCE. 



Until recent years it did not seem that piroplasmosis occurred in 

 France. It had been detected in Algeria, although its existence had not 

 been conclusively proved. Mathis claims to have met with it in the 

 department of the Loire in 1896 and in the Ain in consequence of 

 the importation of Algerian cattle, but its ravages were comparatively 

 trifling. 



