388 MICROBIOLOGY 



Staining. Stained by Romanowsky 's or Laveran 's method 

 the cell body takes a bluish tint and the karyosome a red-violet 

 color. 



PIROPLASMA CANIS. 



Place in nature. Piroplasma canis was first described in 

 Italy by Piana and Galli-Valerio 1 who found it in the blood 

 of a dog suffering from jaundice and fever after living in a 

 marshy locality. The disease caused by this organism was 

 recognized by Hutchin in South Africa as malignant jaun- 

 dice or bilious fever of the dog. It was recognized in France 

 by Le Blanc of Lyons in 1900. Because of certain differences 

 in the symptoms it has been suggested that possibly there are 

 two forms or species of the parasite of canine piroplasmosis. 

 The parasite is transmitted by means of a tick (Haemophysalis 

 laechi) . 



Morphology. In morphology, it differs from Piroplasma 

 bigeminum in that it is larger and is not so constantly bigemi- 

 nate, but appears quite frequently single. Nut-tall and Gra- 

 ham Smith 2 show from 1 to 16 parasites in a single corpuscle 

 and also extra cellular forms. There are, therefore, many 

 minor differences in the descriptions of the different authors.* 

 P. canis described in Italy measured from 2.5 to 3.5 ^ in their 

 largest diameter ; those observed in France from 2 to 4 p. 

 Nocard and Motas state that the parasites are larger in young 

 dogs and that in adult dogs near the close of the disease they 

 appear very much smaller. Nuttall and Graham Smith men- 

 tion the smallest specimens observed in South Africa 0.7 to 

 1.2 /*; the largest 3.6 />t, rarely pyriform bodies measured 

 5 fji. The pyriform bodies are not so common in these species 

 as in P. bigeminum. Nocard and Motas state that they are 

 best observed immediately after the fall of the fever, the only 



'Piana and Galli-Valerio. II moderno Zooiatro (1895) p. 163 

 (cited by Burnett). 



2 Nuttall and Smith. Jour, of Hygiene, Vol. V (1905) p. 237. 



* Nuttall and Smith (Loc. cit.} have brought together these dif- 

 ferences and a perusal of their article on canine piroplasmosis is 

 especially recommended. 



