683 EXPERIMENTAL FARMS 



4 GEORGE V., A. 1914 



the symptoms is not always easy. Some may be observed to be ' going light,' yet 

 they are seen to be good feeders. If picked up, it is found that the flesh has almost 

 entirely disappeared from the breast bone and this should make one suspicious that 

 something is wrong. A yellow or greenish diarrhoea is frequently present in affected 

 birds, and where this is present the type of the disease is most dangerous to the 

 remainder of the flock, as the germs are to be found in the droppings in immense 

 numbers. One of the most frequent symptoms seen early in the course of the disease 

 is lameness, a result of the infection involving a joint of the leg. Lameness is 

 mentioned by persons forwarding fowls for diagnosis more frequently than any other 

 symptom, where our subsequent examinations have proven the trouble to be due to 

 tuberculosis. So frequently is lameness the principal symptom observed that I am 

 at once suspicious of tuberculosis whenever it is mentioned. 



COURSE OF THE DISEASE. 



Fowl affected with tuberculosis may die in a few days from the first appearance 

 of symptoms, or they may linger for weeks, gradually becoming more emaciated as 

 the disease progresses, until they die from exhaustion. The progress is largely 

 dependent on the strength of the invading germ and the natural resistance of the 

 bird. Some outbreaks of the disease follow a more rapid course than others; usually, 

 however, the course in an individual extends over weeks, and sometimes months may 

 intervene before death takes place. 



POST MORTEM FINDINGS. 



The post mortem findings in fowl tuberculosis, when considered in relation to the 

 symptoms and general history, are characteristic. The liver is usually the principal 

 ( rgan affected, and there are lesions, from the size of a pin point to that of a large 

 pea, which are white or yellow in colour. The larger lesions, when cut into, give a 

 gritty sensation as the knife passes through them. These lesions are distinct from 

 the liver tissues and may be quite easily separated from the liver itself. In the more 

 acute cases the liver may be greatly enlarged, even to twice its normal size. This 

 enlargement in chronic cases is noticeable The spleen is usually involved, the lesions 

 having the same characteristics as mentioned for those in the liver. The enlarge- 

 ment of the spleen is usual, and it may be four times its normal size. The intestines 

 may or may not be involved. When lesions are present we find nodules from the size 

 of a small pea to that of a medium-sized nut. The minute dissection of these usually 

 presents a free opening into the inside of the bowel, and at this point of entrance 

 there is an ulceration. It is through this opening from the nodule on the intestine 

 to the interior of the bowel that the bacilli gain access to and are so easily distributed 

 by the droppings. 



Other visceral organs are seldom involved. It is frequently observed that the 

 joints, notably that of either or both hips, may be the seat of tubercular ulcerations. 

 Such an ulceration is the cause of lameness during life. 



PREVENTION AND TREATMENT. 



In the prevention of tuberculosis and other infectious diseases of fowl, sanitary 

 surroundings, with plenty of sunlight and fresh air, are requisites of prime import- 

 ance. In our opinion, these features are best obtained by the use of the modern cotton 

 front house, a number of types having been described by various poultry authorities. 

 Circular No. 7, prepared by Prof. A. G. Gilbert, of the Experimental Farm staff, 

 describes in detail the method of construction, and may be obtained on application. 



