392 Veterinary Medicine. 



ACTINOMYCOSIS OF THB MEDIASTINUM. 



Cattle are especially subject to the invasion of the tissues by 

 the star-fungus, and since once implanted, it progresses in entire 

 disregard of the nature of the tissue in its way, it invades the 

 mediastinum, connective tissue, glands, etc., and may grow to a 

 large size and exercise most injurious compression on the struc- 

 tures involved or adjacent. It is most likely to make its entrance 

 from the gullet or bronchi, but may also reach the glands through 

 the lymph channels from lung, pleura or pericardium. If its 

 presence can be reasonably inferred from the symptoms, and the 

 concurrence of similar formations near the surface, it may be 

 treated, and usually successfully, by the free administration of 

 iodide of potassium, i6 grains to every lOO lbs. of live weight, 

 daily, for 4 or 5 days, then leave an interval of two days, giving 

 a laxative, then another course, and so on for a length of time. 



TUBERCLE OF THE MEDIASTINAI< GLANDS. 



As tubercle is essentially or preeminently a disease of the lym- 

 phatic system, and is concentrated in the lymph glands that re- 

 ceive the drainage from tuberculous tissues, the bronchial and 

 mediastinal glands become involved in nearly all tubercular affec- 

 tions of the bronchia, lungs and pleura, and to a less extent in 

 similar affections of the diaphragm and abdominal organs. So 

 notorious is this, that, in any case of suspicion of tuberculosis of 

 these parts, we make a point, in a necropsy, of first examining 

 the glands in the mediastinum as the most likely to throw light 

 on the more obscure lesions of the tissues. It is no uncommon 

 thing to find the lymph glands in the mediastinum tubercular, 

 when no indication of the disease is found in the lungs, pleura, 

 pericardium or diaphragm. The bacilli have passed through 

 these tissues without causing any lesion, or the slight lesions 

 which they caused have healed, without leaving any appreciable, 

 permanent, structural change. 



Cattle and swine, as being the most frequently affected with 

 tuberculosis, show the mediastinal lesions most commonly, but all 

 animals suffering from thoracic tubercle usually show the lesions 

 in the glands. 



The lesions may be slight, consisting in small pea-like nodules 



