Piroplasmosis

Abstract

RESUME. 1. Piroplasmosis of the horse is a disease with periods also pronounced by physical-chemical alterations of blood and serum. 2. The haemolysis, produced by the intra-globular parasites, has to be considered to be the cause of a great number of physical-chemical symptoms of the serum, for the latter depend in several points on the state of the blood corpuscles. 3. Volume of blood corpuscles, viscosity, and specific gravity of the blood all decrease. Never was an increase of the viscosity noticed; contrary to what is observed in horse-sickness. 4. Viscosity, specific gravity, conductivity, and surface tension of serum also decrease, the latter especially in the beginning of the disease. The osmotic pressure of serum decreases in every instance; in four cases out of six an increase precedes, and can amount even to more than 100 per cent. The specific gravity decreases in four instances and increases in two instances. 5. Physical-chemical alterations emphasise themselves by the methods in use before the temperature starts to rise (conductivity the first day, depression of freezing point, viscosity, surface tension, and specific gravity). Therefore, if we call incubation period the time between infection and the appearance of the first signs of the disease, it would be in some of our cases of piroplasmosis not more than twenty-four hours (2840, 2841); in other cases (3260, 3248, 3249), about four days; that is to say, much shorter than when only considering the appearance of fever. 6. The physical-chemical alterations of the urine are not typical and regular, like those of serum and blood; some of them are extraordinary, all show dependence on the state of the serum and demonstrate again the regulatory functions of the kidneys.