500 DISEASES, PARASITES, AND ENEMIES 
of the factors in poultry hygiene. The term “ clean birds ’? means 
the immediate checking of any symptoms of disease. This neces- 
sitates not only the treatment of sick birds, but their immediate 
isolation, and the proper disposal of dead ones. 
The only safe way to dispose of dead birds is to burn them, 
which is especially necessary if the diseases are highly infectious. 
If buried, it should be at least three feet deep, to prevent the possi- 
bility of dogs or wild animals digging them up. The danger of 
infection, however, is never entirely averted except by burning. 
A most unwise practice is to throw the bodies into the bushes, or 
other out-of-the-way spot, whence the infection, if present, may 
be carried broadcast. 
The Diagnosis of Disease.—The first question which confronts 
a poultryman with sick birds is, ‘‘ What ails my birds?” It is 
obviously necessary to determine the nature of the trouble before 
instituting preventive or curative treatment. But it must be 
understood that the average poultryman or farmer cannot diagnose 
poultry diseases, either by external or internal examination, with 
any degree of certainty. In most cases it is possible by a careful ex- 
amination to locate the trouble, andsthereby to place it in a general 
group of disorders which affect this or that particular organ in a 
given way. There are two general methods of making a diagnosis, 
—external examination and post-mortem examination internally. 
An external examination may show certain well-defined symp- 
toms which are almost always associated with illness of any nature, 
and which must be understood before attempting to make an 
exact diagnosis. 
Symptoms to look for are: A lack of interest in what is going 
on about it; a dumpy appearance, caused by contraction of the 
neck, ruffled feathers, sitting in one place, usually in a dark corner 
out of the way of other birds; the eyes closed most of the time, 
giving the bird a sleepy appearance; the wattles and the comb 
shrivelled up and dark or purple in color, or very pale; decided loss 
of appetite. When these symptoms are noted, the bird should be 
isolated, and an attempt made more accurately to define the trouble. 
The following classification* of external symptoms may assist ° 
the one making the diagnosis in determining which of a number 
of specific diseases is really present in the specimen. Before 
accepting this as the direct cause, he should compare the symptoms 
with an accurate pathological description. 
*After Raymond Pearl, Maine Experiment Station. 
