824 MICROBIOLOGY OF DISEASES OF MAN AND DOMESTIC ANIMALS 



Ulcers caused by amoebae are almost always situated in the large 

 intestine; consequently, the symptoms of amoebic dysentery are those 

 of inflammation of that part of the body. There is usually abdominal 

 pain, accompanied by the passage of frequent, blood-stained stools with 

 mucus. The infection may, however, be accompanied by no marked 

 symptoms and there may be no diarrhoea. There are usually developed 

 rhore general symptoms, such as fever and loss of flesh. The onset is 

 frequently very gradual and insidioiis and the disease runs a chronic 

 course. If amoebic dysentery causes death, it is usually does so by per- 

 foration of the bowel with resulting peritonitis, by haemorrhage from 

 the erosion of a blood vessel, or as the result of abscess of the liver. 

 Liver abscesses occur not infrequently in amoebic dysentery. 



Amoebic dysentery is cured with difiSculty although emetine, a 

 product isolated from ipecac, has recently been, found of great value. 

 Since the encysted amoebae are killed by heat, it can be avoided ty 

 eating and drinking only foods and liquids that have been cooked. 



I Entero-hepatitis of Turkeys 

 Emtamceba meleagridis — Smith, 1895 



I 



Entero-hepatitis, or black-head, of turkeys is caused by Eniamceha 

 meleagridis. The disease is widespreaid throughout North America. 

 It is a very fatal affection and on many farms it makes the raising of 

 turkeys a difficult problem. The diseasfe is characterized by thick- 

 ening and ulceration of the caeca, and by extensive necrosis of the liver. 

 -Entamoeba meleagridis is a small amoeba measuring about 8/x to lo/i in 

 diameter. Turkeys probably become infected with this parasite by 

 swallowing its encysted forms; young turkeys may possibly become 

 infected from encysted amoebae, which adhere to the shells from which 

 they were hatched. 



There has been no efficient treatment devised for the disease, since 

 it is usually not noted until far advanced, but it can be avoided through 

 keeping healthy stock on land which has never been infected by drop- 

 pings from infected birds, and by carefully wiping eggs intended for 

 hatching with formalin. 



Flagellata (Cohn emend. Biitschli) 



The herpetomonads and the trypanosomes are the most important of the para- 

 sitic flagellates. - 



