BOVINE PIROPLASMOSIS, 



421 



The urine may present a variety of tints, derived from hemoglobin. 

 The liver is often engorged with blood and the gall bladder always 

 distended. 



When convalescence sets in, icterus appears; but it is a special 

 kmd of icterus, depending on changes in the haemoglobin— in fact, a 

 hsemaphaeic icterus. Histological examination of the blood furnishes 

 the explanation of the disease by revealing the presence of the parasite. 



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Fig. 196.— Slow formation of free germs. 1, Pear-shaped organisms with large chro- 

 matic element and a flagellum; 'J, newly-developed round cell without chromatic 

 element ; 3, 4 and 5, formation of the chromatic elements ; 6, the germs about to 

 escape; 7, the germs freed. (After Lignieres.) 



Pathogeny. The parasite is the PiroplKsimi liii/cDiinum, which is 

 easily demonstrated by drying the blood, fixing it and staining with 

 very ^veak methylene blue. The blood is light in colour and pale, 

 and the serum is tinted by the dissolved hemoglobin. The blood 



3 



4 



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Fig. 197. — Kapid formation of free germs. 1, Newly-developed round parasite without 

 distinct germs ; 2, round parasite with two germs ; 3, the germs approaching the 

 surface and undergoing development; 4, the germs beginning to grow outwards 

 preparatory to formmg new round parasites ; 5, the process previously noted is 

 becoming more marked ; the protoplasm of the cell is undergoing degeneration, 

 and scarcely stains at all ; 6, round parasites. This completes the cycle. These 

 parasites (6) are similar to (1). (After Lignieres.) 



corpuscles diminish in number with extreme rapidity while the para- 

 sites are developing, and in twenty-four or forty-eight hours may fall 

 from some sis millions and a half, the normal number, to one million 

 or even to two or three hundred thousand red blood corpuscles per 

 cubic millimetre. 



This destruction is due to the action of the piroplasmata, as may 

 be shown by staining with a -5 per cent, methylene blue or carbolised 

 thionine. These parasites usually assume a simple jjyriform shape, 

 and two or three may be found in one blood corpuscle. The number 



