318 HEALTH, DISEASE AND ENEMIES 



sites take theif nourishment from the feed which the bird 

 eats. They also attach themselves to the walls of the intes- 

 tines, and suck nourishment from the blood and the digested 

 feed material. Every precaution should be taken to keep 

 a flock free from these parasites, for if once present, they 

 are apt to spread until all of the birds are affected. Birds 

 which die should be cut open, and the intestinal tract ex- 

 amined to see if there are any worms. If present, steps should 

 immediately be taken to rid the whole flock of them. The 

 best way is to give the birds a purgative, such as Epsom 

 salts or castor oil, withholding feed from them until two or 

 three doses of the medicine have been given, when the worms 

 will usually be discharged. 



EXTERNAL PARASITES 



The most common group of animals which feed on live 

 birds are the external parasites. These live wholly on thp 

 outside of the body. Some get their nourishment by sucking 

 the blood, others feed on the skin or the quills of the feathers, 

 others consume the waste products thrown off from the body. 

 These are most numerous in warm weather, and multiply 

 very rapidly in unsanitary quarters. There are four common 

 types of external parasites with which every poultry keeper 

 should be familiar: lice, red mites, depluming mites, and 

 scaly leg mites. 



Body lice (Fig. 174) are numerous on all full grown 

 poultry. They are yellow in color, and about the size of the 

 head of a pin, most of them are long and slender. In adult 

 birds body lice are usually found in the fluff and the hind 

 part of the body, especially about the vent and sometimes 

 under the wings. They subsist on the skin, particularly 

 the scales of dead skin which peel off. Body lice stay on the 

 birds all the time, never leaving the body, and their presence 

 is very irritating. There are three methods for getting rid 

 of them. The first and simplest is to provide a dust box 



