788 Piroijlasmohiis of Horses. 



observed (Eassie frequently observed a luxation of the patella as a 

 result of a relaxation of the thigh muscles). In donkeys icterus is also 

 rarely present, while the urine frequently shows a red coloration; a 

 vesicular eruption is also observed in some cases on the back, less fre- 

 quently also on other parts of the body, and is followed by loss of the 

 hair. 



The autopsy reveals a large quantity of pale yellow fluid in the 

 abdominal cavity and in the pericardium. 



Piroplasma may be demoustrated in the circulating blood in variable numbers. 

 While in severely acute cases and at the height of the fever they may be found 

 in 50-60% of the red blood corpuscles, and some of these may contain as many as 

 5-ti parasites, in chronic cases hardly 1-2%, are infested. 



Course and Prognosis. Cases witli severe onset, especially 

 iilTeat debility, high fever, numerous hemorrhages and hemo- 

 globinuria, likeAvise cases of a chronic character, usually run 

 an unfavorable course, wdiereas cases which are acute, but 

 without severe sjTnptoms, promise a favorable termination. In 

 these cases the improvement sets in after about eight days, 

 Avhereupon recovery progresses slowdy (according to Eickmann 

 the benign forms are as a rule relapses). 



Diagnosis. The disease differs from horse sickness princi- 

 pally by the i^resence of marked icterus, and on the other hand 

 by the "absence of extensive edematous swellings. A positive 

 diagnosis is however only possible by the demonstration of piro- 

 plasma in the red blood corpuscles, or then by the infectious- 

 ness of the filtered blood in horse sickness, as well as in perni- 

 cious anemia. The microscopical examination makes a positive 

 diiTerentiation of pirolasmosis from trypanasomiasis possible 

 aside from the fact that this disease is less acute, and does not 

 show icterus and such marked debility. Besides this the s^anp- 

 toms of piroplasmosis to which Italian observers have repeat- 

 edly pointed, closely resemble also those of influenza and pur- 

 pura hemorrhagica. 



Treatment. Horses which are attacked in the pastures 

 should immediately be placed in stables or in dry shady places ; 

 where they should be freed from ticks, and nourished as freely 

 as possible. The threatening heart weakness is combatted 

 with digitalis or camphor, the constipation first with calomel, 

 later with salines. Arsenical preparations are recommended for 

 the after treatment. 



The specific treatment has so far failed to give uniform results. Formerly 

 large doses of quinine (10-20 gni.) alternating with ammonium chloride were 

 given, whereas recently mercurial and arsenical preparations are preferred. Thus 

 Baroni recommends the Hydrarg. biiodatum injected into the muscle, and 

 Laf argue, Lussault & Savary "also obtained good results from this treatment (1 gm. 

 Hydrarg. biiod., 2 gm. iodide of potassium, 100 gm. aqua; 10-20 gm. daily)- 

 ^^aikowitsoh and Marzinowski & Bielitzer praise intramuscular injections of corrosive 

 sublimate (10 cc. of a 2% solution daily, 3-5 times in all), and according to 

 Michin & Yakimoff it is possible to reduce the mortality by this treatment to 20%. 

 The subcutaneous application of arsenious acid, and of atoxyl has not proved 

 effective. 



