880 Gangrene of the Skin. 



Chemical substances circnlating- in the blood may cause 

 dry gangrene of the skin. This is observed most frequentl}- in 

 ergot poisoning in which parts of the skin and even whole parts 

 of the extremities, the ears, the tail, in fowls the comb, the 

 wattles and tip of the tongue, in ducks the beak, etc., mortify 

 and are cast off (Ergotisnius gangraenosus). The cutaneous 

 gangrene occurring sometimes in clover disease is likewise 

 caused by chemical poisons. Necrosis of the skin in horses is 

 also sometimes a s^nnptom occurring in lupinosis; Lathyrus 

 sativus, lucerne and buckwheat may produce a like action on 

 the uncolored parts of the skin. A similar gangrenous inflam- 

 mation develops on the extremities of horses on the coronets 

 and fetlocks, sometimes mtliout any assignable cause (socalled 

 necrotic eczema) in which, however, the injurious effect is prob- 

 ably due to bacteria. 



The frequent skin gangrene occurring in swine is mostly 

 caused by the bacilli of swine erysipelas (Jensen), Avliich mul- 

 tiply in the vessels of the skin, producing in mild cases a serous 

 infiltration (urticaria) and in severe cases a tissue necrosis. 

 The same thing may also be noticed quite frequently in swine 

 plague or hog cholera. In the course of purpura hemorrhagica, 

 gangrene of the skin may occasionally be observed. Other 

 pathogenic bacteria (Bac. necrophorus and perhaps others) 

 doubtlessly play a part in cases where a quick destruction of 

 neighboring tissues results from insignificant injuries. 



In the Hungarian stnd at Mezohegves in a stable where a slight inflammation 

 of the heels of the animals had been noticed every year in tlie mouths 

 of July and August, in the year 18S0 gangrenous inflammation of the fold of the 

 fetlock occurred among 1 and 2 year old stallion foals which were kept here, and 

 assumed an enzootic character. Thirty foals became affected and the disease assumed 

 such a severe character that in some cases gangrene of the tendons, ligaments 

 and bones developed. The cause was probably an infection with the bacillus of 

 necrosis. 



Continuous pressure on the skin at times causes mortifica- 

 tion in consequence of disturbing its nutrition, and this may 

 frequently be seen in animals lying on the ground for a long 

 time, on parts of the skin which immediately cover bones. The 

 same is brought about by severe contusions. 



Finally, corrosive substances such as concentrated acids, 

 alkalies, etc., cause a mortification of the parts that are touched 

 immediately as well as neighboring portions of skin, in conse- 

 quence of coagulation and destruction of the cell albumen. 



Symptoms. Gangrene of the skin is preceded either by 

 acute eczema, in which case reddening, increased sensitiveness 

 and swelling of the skin are noticed, or it presents itself im- 

 mediately without such prodromal symptoms. After the onset 

 of necrosis the skin becomes brown, and at the same time its 



