296 THE TUBERCLE BACILLUS 



Horses. Tuberculosis is rarely seen in horses. When it occurs it is generally 

 of the abdominal type. A pulmonary infection is occasionally seen which 

 may assume the character of a miliary tuberculosis or of diffuse infiltration 

 of the lung, and large sarcoma-like masses may also occur. 



[F. Griffith (for the English Commission) investigated five cases of equine 

 tuberculosis. From three of these bovine tubercle bacilli of standard viru- 

 lence were isolated ; the bacilli obtained from the remaining two had the 

 cultural characteristics of the bovine tubercle bacillus associated with a low 

 degree of virulence for all the test animals calf, rabbit, monkey, guinea- 

 pig, etc. By prolonged passage experiments the virulence of the latter 

 bacilli was increased to that of the bovine tubercle bacillus.] 



Cats. Cats are rarely tuberculous but when the disease occurs the lesions 

 are similar to those seen in dogs. The commonest form is a localized infection 

 of the alimentary canal. [Investigations by A. S. Griffith and F. Griffith 

 show that the bovine tubercle bacillus is the cause of natural tuberculosis 

 in the cat.] 



Birds. Tuberculosis is a very common disease among birds : fowls, 

 pheasants, guinea-fowl, partridges, peacocks, parrots, birds of prey, etc. 

 are, all of them, very frequently infected. [The disease sometimes appears 

 as a rapidly fatal epizootic among farm-yard fowls.] 



Tuberculosis in birds is usually primary in the alimentary tract developed [it is 

 affirmed] as a result of swallowing the excreta of tuberculous animals or infected 

 human sputum. 



[The investigations of the English Commission do not support this view of the 

 setiology of avian tuberculosis. Their experiments would tend to show that birds 

 (excluding the parrot) are not susceptible to mammalian tubercle bacilli.] 



Tuberculosis in parrots is often associated with a bacillus of the human type 

 and is due to infection from the human subject (Eberlein, Cadiot, Straus). From 

 the experimental point of view parrots are most easily infected with the human 

 tubercle bacillus, next with the bacillus of the bovine type, they appear to be 

 least susceptible to the avian type. 



In birds the liver and spleen are the organs most commonly affected : pulmonary 

 lesions are rare though the lungs may become infected in the last stages of the dis- 

 ease. Except in parrots, tuberculosis of the skin, mucous membranes or joints 

 is rarely seen. The disease may be congenital in origin the egg becoming infected 

 in the oviduct (Baumgarten, L. Rabinowitsch, Weber and Bofinger). 



The histological appearances of tuberculous lesions in birds are unlike those in 

 mammals : and moreover present different features in the various species. Not 

 uncommonly the viscera will be found to be infiltrated with bacilli while there are 

 no visible tubercles. 



Gold-blooded vertebrata. Tuberculous lesions have been found in the boa- 

 constrictor, the python, the ringed snake [Coluber natrix Linn. ] and the 

 frog. Dubard investigated a tuberculous condition in the carp caused by a 

 bacillus apparently very closely related to the human bacillus. 



The bacillus of ichihic tuberculosis is very similar to the human tubercle bacillus 

 except that it grows badly at temperatures above 25 C. and in this respect resembles 

 the para-tubercle or acid-fast bacilli (vide infra}. 



Cultures obtained from the carp are pathogenic to frogs, toads, lizards, tortoises, 

 adders, the common grass snakes, carp and other fish of the same genus, etc. The 

 bacilli are non-pathogenic to guinea-pigs and birds ; but by passage through guinea- 

 pigs the organism becomes virulent for that rodent. Ichthic tubercle bacilli when 

 inoculated into rabbits or guinea-pigs behave in the same way as human tubercle 

 bacilli which have become avirulent by prolonged culture on artificial media (Krom- 

 pechen). Tuberculin prepared from a culture of an ichthic bacillus, which Ramond 

 and Ravaud believe to be the same as the tuberculin obtained from a culture of the 

 human bacillus, does not, when administered in ordinary doses, give the same 

 reaction as Koch's tuberculin but behaves more like that produced from a culture 

 of an avirulent human bacillus (Krompecher). 





