114 POULTRY DISEASES AND THEIR TREATMENT. 



increased blood pressure may result in a rupture of the heart 

 or one of the large vessels. 



Treatment. — The accident can not be predicted and treatment 

 is impossible. 



Prognosis. — The bird dies in a short time. 



DISEASES OF THE BLOOD. 



Various cases of an alteration in the number of white cor- 

 puscles in the blood of fowls have been described. Most of these 

 descriptions are based on from one to three cases, and from the 

 descriptions it appears that the investigators have found several 

 different blood diseases. Most of these diseases when tested 

 did not prove infectious. They are impossible to distinguish 

 except by microscopic examination and most of them are prob- 

 ably quite rare. Only one of these diseases seems to be of any 

 economic importance. This is Infectious Leuk(smia, first de- 

 scribed by Moore (Ann. Rep. Bur. An. Ind. 1895-1896). 



Infectious Leukcemia. 



This is a bacterial disease often mistaken for fowl cholera but 

 caused by a different species of bacteria and the lesions produced 

 are somewhat different. 



Diagnosis. — ^The following symptomatology is quoted from 

 Moore : "From the statement of the owners of the fowls in the 

 different outbreaks and from the appearance of those in which 

 the disease was artificially produced, little can be positively 

 recorded concerning the distinctive or characteristic symptoms. 

 The only fowl examined ante-mortem from the natural outbreaks 

 was first seen only a few hours before death, when it was unable 

 to stand. If held in an upright position, the head hung down. 

 'There was a marked anaemic condition of the mucosa of the head. 

 It had an elevation of nearly 3 degrees of temperature. An 

 examination of the blood showed a marked diminution in the 

 number of red corpuscles and an increase in the number of white 

 ones. In the disease produced artificially by feeding cultures of 

 the specific organism there was in most cases a marked drowsi- 

 ness and general debility manifested from i to 4 days before 

 death occurred. The period during which the prostration was 

 complete varied from a few hours to two days. The mucous 

 membranes and skin about the head became pale. There was 



