POULTRY DISKASES AND THEIR TREATMENT. 53 



than that the wattles and comb may be yellowish. This also 

 occurs in other liver diseases. Post-mortem examination shows 

 the gall bladder greatly distended with bile. 



Treatment. — Give greater variety of food, especially more 

 green food. Give Epsom salts frequently. Megnin recom- 

 mends 3/2 to I grain of aloes. 



This completes the list of the liver diseases most commonly 

 treated as such by poultry veterinarians. There are a number 

 of other diseases which especially affect the liver or are caused 

 by deranged function of this organ. These may mo.st con- 

 veniently be mentioned at this place. 



Blackhead (Infectious Bntero'Hepatitis) . 



Blackhead is essentially a disease of turkeys.^ It is not the 

 intention of this work to treat diseases of poultry other than 

 fowls. Consequently little will be said about this disease except 

 as it applies to fowls. If further information is desired the 

 reader is referred to the Rhode Island Experiment Station, 

 Kingston, R. I., for bulletins relating to this disease. That sta- 

 tion has been and still is studying this disease in a most thor- 

 ough way. 



Blackhead is a contagious disease affecting the liver and in- 

 testines, especially the blind pouches or ceca of the latter. The 

 disease is very quickly fatal among turkeys. The turkey is 

 apparently more susceptible than any other bird to this disease. 

 In certain portions of this country where once turkey raising 

 was a promising industry it has been practically annihilated. 

 The disease is not usually as fatal to adult chickens but may 

 cause very serious loses at times. It is now believed by several 

 prominent investigators of this disease that white diarrhea, so 

 destructive to young chicks, is caused by the same organism as 

 blackhead. For further discussion of this see Chapter XIX. 



The cause of blackhead disease according to Dr. Theobald 

 Smith (Bur. An. Ind. Bui. No. 8) is a minute parasitic proto- 

 zoan known as Amoeba meleagridis. More recently Drs. Cole 

 and Hadley of the Rhode Island Experiment Station have 

 claimed that the causative organism belongs to another group of 

 protozoa known as Coccidia. Dr. Smith, however, still main- 

 tains that the former organism is concerned in the disease. The 

 point to this discussion lies in the fact that the Coccidium has 



