218 Purpura Hemorrhagica. 



According to the bacteriological examinations of Lignieres (1895- 

 1898), the internal organs and the blood of animals dead from purpura 

 hemorrhagica contain, as , a rule, besides other bacteria, streptococci, 

 principally pyogenic, and more rarely streptococci of distemper. The 

 bacillus equisepticus is also met with relative frequency (among 26 

 cases this organism was found in 9 instances), and this seems to indicate 

 tha^t both diseases are closely related. This may be also substantiated 

 by observations in Argentine where influenza occurs mostly in a very 

 acute form without inflammation of the thoracic organs and purpura 

 hemorrhagica very frecjuently develops as a sequel (similar observa- 

 tions were made by Theiler in Transvaal). Accordingly both bacteria 

 play a part in the etiology of purpura hemorrhagica, the severe symp- 

 toms, however, are caused by the streptococci or their toxins. 



Lignieres failed to produce the disease even in a single instance 

 in its characteristic form, in spite of the fact that he injected horses 

 intravenously with quantities up to 8000 g. of streptococci culture, and 

 subsequently exposed the animals to cold rains. He considers the im- 

 portance of the streptococci proven, however, from the observations 

 made by Frasey, w^ho has seen a disease corresponding clinically with 

 purpura hemorrhagica develop in two horses, which had been injected 

 with highly virulent cultures of streptococci for the preparation of anti- 

 streptococcic serum. The fact that purpura hemorrhagica develops 

 quite frequently as a sequel to strangles and influenza, appears to 

 indicate the indirect association of streptococci with the disease (Bruin 

 observed the development of purpura hemorrhagica in its severe form 

 m two cases after the accidental injury of a vein in puncturing an 

 abscess in strangles) 



Cadeac also considers purpura hemorrhagica as an intoxication, which, 

 according to his view develops as the result of vasodilatatory toxins of various 

 bacteria, especially of different pyogenic cocci, in animals which have been weak- 

 ened by another disease. Mouilleron & Eossignol, as well as Cormier, also attribute 

 the greatest importance to the stieptococci, especially on the ground of the favorable 

 results which they have obtained in the treatment of the disase with antistrepto 

 coccus serum, although they do not deny the possible action of other micro-organisms. 

 Coquot considers the disease as a Pasteurellosis. 



Contrary to other observers Javorsky succeeded in only 7 cases out of 148, 

 in demonstrating the occurrence of purpura hemorrhagica as a sequel to other 

 affections (twice strangles, 5 times pleuro-ijneumonia). Wohlmuth also believes 

 that the disease may develop independently, and therefore he distinguishes an 

 idiopathic and symptomatic form, in which the vascular system, especially the intima 

 of the capillaries, is always the point of attack for the toxins which produce the 

 disease. 



Recently Baruchello & Nori, and later also Perrueci expressed the improbable 

 view that purpura hemorrhagica represents a piroplasmosis, as they found protozoa 

 resembling piroplasma in the red blood corpuscles ot four affected horses. However, 

 the severe initial symptoms (high fever), which were observed it these cases indicate 

 that these affections were not true cases of purpura hemorrhagica. 



The mode as well as the determining factors of natural 

 infections are not yet sufficiently clear. It has been observed 

 that the disease occurs principally in badly ventilated stables, 

 with dirty floors, but it also occurs in well groomed horses kept 

 under favoral)le conditions. The disease is most frequent in the 

 spring and in the beginning of summer. 



The age of the animals appears to have no influence except 

 that colts imder two years of age do not become affected (Dieck- 

 erhoff) ; otherwise there appears to be no factor which affects 



