THE PIGEON BOOK 61 



After a season's rest from breeding, when the moult 

 has taken place, the feathers will be stronger, richer, and 

 more lustrous, and the birds will probably show no more 

 symptoms of disease. 



In all cases where the disease is due to kidney and blood 

 trouble as I have described, the birds become heavy and 

 the skin hot and there is difficulty in flying and breathing. 



(2) Skin disease — Acarus (the tick or mite). 



At one time I considered that feather rot in all forms 

 was due to one and the same cause, but careful examina- 

 tion of the subjects affected has convinced me this is not 

 the case. 



When the trouble arises from kidney disease or earthi- 

 ness of the system the subject becomes fat and loses power 

 of flight.^ The secretions do not show the same tint of 

 the urine as in healthy birds. 



But when the trouble arises from parasitic causes, which 

 is often the case, there is no fatty degeneration, and the 

 only symptom is the attack of the parasites on the feathers, 

 generally in small round patches on the breast, and some- 

 times on the shoulders ; starting with a small patch, it may 

 be as large as a bean and extending in size. 



In order to ascertain if the disease is of this nature some 

 small feathers in the immediate vicinity of the trouble 

 should be removed ; they should be carefully laid on a 

 clean piece of white paper, and the root of the feather 

 examined with a pocket lens or microscope of low power. 

 If small, moving particles can be seen moving about near 

 the root of the feather there is no doubt as to the nature 

 of the disease. 



The disease in this form is, I think, somewhat akin to 

 mange in dogs and horses, or sheep-scab in sheep, with 

 this difference : I cannot find traces of contagion amongst 

 pigeons, but it may be that certain birds are immune from 



