22,1 Sellards and Leiva: Amoebic Dysentery 13 



injection. These two experiments do not exhaust the possibilities 

 of preventing dysentery in kittens by the prophylactic use of 

 emetine. 



Quinine. — For the most part indifferent or poor results have 

 been reported in the treatment of amoebic dysentery by quinine, 

 although this drug is toxic for cultural amcebse in vitro and 

 produces very definite effects therapeutically in malaria. A few 

 years ago Brooke (l) reported rather favorable results in the 

 treatment of chronic amoebic infections in man. 



Our first test of quinine on animals was made with a cat 

 (No. 27), which for two days had failed to show any response 

 to papaverine. Under large doses of quinine dihydrochloride 

 (200 milligrams per kilogram in 1 to 50 solution) the symptoms 

 improved promptly, and the amoebae for a short time became 

 very scarce, though it was not possible to eradicate the infec- 

 tion. This temporary improvement under quinine of a well- 

 established infection is in marked contrast to the failure of 

 emetine under similar conditions. A second animal (No. 29) 

 was treated by rectal injection with quinine in 1 to 100 dilution, 

 immediately after the diagnosis was established. On the next 

 day there was little change; another injection of quinine was 

 given (200 milligrams per kilogram of body weight), increasing 

 the concentration* to 1 to 50. After a half hour some mucus 

 was expelled which was free from amcebse. On the next day 

 the stools were negative. Quinine was given once more (200 

 milligrams per kilogram) and then discontinued. The animal 

 remained in good health for many days, and the stools were 

 formed and negative for blood and amoebae. Then a relapse 

 occurred. No further treatment was given, and death took 

 place thirty-one days after the inoculation with amoebae. A 

 third cat (No. 30) was treated more intensively. After an incu- 

 bation period of three days, this animal was passing blood- 

 streaked mucus rich in amoebae. Injections of quinine (200 milli- 

 grams per kilogram of body weight in 1 to 50 dilution) were com- 

 menced at once and continued daily. On the day after the first 

 treatment, the stool showed a trace of tarry blood, and one 

 amoeba was found. Thereafter the specimens were negative 

 for blood and amoebae. On the seventh day of treatment this 

 cat, though strong and active, showed slight muscular tremors 

 and a little nystagmus. Quinine was therefore discontinued. 

 This animal has remained free from symptoms, and no amoebae 

 have subsequently been found; the last observation was made 

 forty days after inoculation. 



