SYMPTOMS 327 



differed from the diphtheria bacterium in man. Loir and 

 Ducloux isolated a still different organism. The writer found 

 in the exudates of the earlier stages of the disease a bacterium 

 belonging to the septicaemia hemorrhagica group. It was 

 rapidly fatal to rabbits but the diphtheretic lesions could not 

 be produced by inoculation in fowls. There are marked differ- 

 ences in the different bacteria isolated and suspected of etio- 

 logical significance. It is not positive, however that the same 

 disease was studied by the different writers. There is little doubt 

 of the specific nature of the disease. It is usually introduced 

 into a flock by the exposure of the birds to sick ones at shows 

 or by bringing affected birds on the premises. The contagion 

 may be carried by birds which have the disease in so mild a 

 form that the\^ show no symptoms of it. There is a general 

 belief that the disease may be developed b}- exposure of birds 

 to draughts of air or by keeping them in damp, filthy and 

 badly-ventilated houses. It is presumable that this belief in 

 its etiology is not well founded because of confusion existing 

 concerning the earh' symptoms of acute diphtheria and those 

 of all stages of the clironic form and those of simple colds and 

 catarrhs. Dampness and lack of ventilation no doubt favor 

 the maintenance of the virus when introduced and predispose 

 the birds to the disease. The specific cause of the disease 

 known as diphtheria or roup in chickens and pigeons in the 

 opinion of the writer is not known. 



i^ 247. Symptoms. There is a watery secretion from 

 the nostrils and often from the eyes, with general weakness 

 and prostration greater than would be expected from simple 

 catarrh. The birds sit with the back arched, the head and 

 neck drawn down towards the body, the plumage roughened ; 

 the respiration is more or less obstructed, rapid and audible, 

 the vision is impaired and swallowing is difficult. There is 

 frequent shaking of the head, sneezing and expectoration of 

 mucous secretions. If the mouth is examined at this early 

 period the tongue is found to be pale, while .small grayish 

 spots, shaded wath black and slightly projecting above the 

 surface are seen along the border, the upper surface or at 

 the base. 



