POULTRY DISEASES AND THEIR TREATMENT. I29 



observed several lice clinging to the body of a fly parasitic upon 

 chickens. Lice are so much more common than the parasitic 

 fly that it is probable that this insect is of little real importance 

 in the distribution of the lice. 



All the lice breed very rapidly. In 8 weeks the third genera- 

 tion is mature and in this generation the estimated number of 

 the offspring of a single pair is 125,000 individuals. It seems 

 important to eradicate an infestation if possible as soon as dis- 

 covered. However, if kept under sanitary conditions and fur- 

 nished with plenty of attractive dust, vigorous birds will hold 

 external parasites in check. ' With some attention to sick birds, 

 setting hens and young chicks, the parasites will give little 

 trouble on a plant conducted with due regard to the principles 

 of hygiene and sanitation (cf. Chap. II). 



Diagnosis. — "It should be remembered at all times that the 

 external animal parasites are the most common and frequent 

 cause of trouble in the poultry-yard and pigeon-cote. If the 

 birds are not thriving and conducting themselves satisfactorily, 

 look for these pests, take measures to repress them, and in most 

 cases the results will be surprising and gratifying. When any- 

 thing is the matter with a horse the maxim is examine his feet, 

 and when anything is found wrong with poultry or other domes- 

 ticated birds, the maxim should be look for lice." (Salmon.) 



Adult hens may harbor quite a number of these parasites with- 

 out shov/ing any symptoms which indicate their presence. If 

 they are unthrifty and broody hens leave their nests they should 

 be examined for lice. The biting and digging of the claws of 

 the lice may cause sores and the nervous irritation and loss of 

 sleep may cause general debility and bowel trouble. Little chick- 

 ens are very susceptible and often die. Lice are frequently 

 found in large numbers on birds suffering from roup, gapes, etc. 

 In some cases their presence has rendered the birds more sus- 

 ceptible to other disease, while in others it is probable that the 

 birds lack sufficient energy to dust themselves. 



The sure test for the presence of lice is, of course, finding the 

 lice. Part the fathers under the wing, on the back and around 

 the vent and examine the exposed skin. Examine the head and 

 neck feathers and look between the large feathers of the wing. 

 When present the parasites are easily found by anyone who is 

 familiar with them. It seems incredible that serious infesta- 

 tions can escape the eye of any poultryman. 



