MANGE. 351 



to the head, or (lo"\viiw'ard to the withers and back, and occasionally extends 

 over the whole carcass of the horse. 



One cause of it, although an unfrequent one, has been stated to be 

 neglected or inveterate surfeit. Several instances are on record in which 

 poverty of condition, and general neglect of cleanliness, preceded or pro- 

 duced the most violent mange. A remark of Mr. Blane is very important: 

 — ' Among the ti'uly healthy, so far as my experience goes, it never arises 

 spontaneously, but it does readily from a spontaneous origin among the 

 unhealthy.' The most common cause is contagion. Amidst the whole hst 

 of diseases to which the horse is exposed, there is not one more highly 

 contagious than mange. K it once gets into a stable, it spreads through 

 it, for the sHghtest contact seems to be sufficient for the communication of 

 this noisome complaint. 



If the same brush or currycomb is used on all the horses, the propaga- 

 tion of mange is assui^ed ; and horses feeding in the same pasture with a 

 mangy one rarely escape, from the propensity they have to nibble one 

 another. Mange in cattle has been propagated to the horse, and from the 

 horse to cattle. There are also some well-authenticated instances of the 

 same disease being communicated from the dog to the horse, but not from 

 the horse to the dog. 



Mange has been said to originate in want of cleanliness in the manage- 

 ment of the stable. The comfort and the health of the horse demand the 

 strictest cleanliness. The eyes and the lungs frequently suffer from the 

 noxious fumes of the putrefying dung and urine ; but, in defiance of 

 common prejudice, there is no authentic instance of mange being the 

 result. It may, however, proceed from poverty. When the animal is 

 half starved, and the functions of digestion and the power of the consti- 

 tution are weakened, the skin soon sympathises, and mange is occasionally 

 produced, instead of surfeit and hide-bound. Every farmer has proof 

 enough of this being the case. If a horse is turned on a common where 

 there is scarcely sufficient herbage to satisfy his appetite, or if he is 

 placed in one of those straw-yards that are under the management of 

 mercenary and unfeeling men, and are the very abodes of misery, the 

 animal comes up a skeleton, and he comes up mangy too. Poverty and 

 starvation are fruitful sources of mange, but it does not appear that filth 

 has much to do with it, although poverty and filth generally go hand in 

 hand. The actual cause of mange, however, is the existence of a parasite 

 burrowing in the skin, the knowledge of which is comparatively of recent 

 date in this country, although it has been for some time known on the 

 Continent ; the name of the insect is the Acarus equi, and is precisely 

 analogous to the parasite producing the itch in man — it belongs to the 

 family of mites, one of the most widely disseminated famihes in the 

 animal creation ; they are found in the most dehcate preparations in our 

 museums ; in all kinds of preserved animal and vegetable substances ; in 

 our very food — in the skin of man, producing the itch, in the skin of the 

 horse and the dog, producing the mange. It is to the valuable aid of the 

 microscope we are indebted for the discovery of this most mischievous 

 and troublesome insect — a regular set of scourgers, burro^ving under the 

 epidermis, or scarf-skin in man, and in the horse, sucking up and thus 

 clearing away the impurities on the skin, which filth and dirt accumulate, 

 and in return depositing their eggs, rearing their progeny, and giving 

 unmistakeable evidence of their existence. The acarus has eight legs, 

 most of which terminate in a cup-like form, which acting hke a sucker, 

 enables the mite to adhere to the skin in a most pertinacious manner. 

 It is to a paper by Mr. Erasmus Wilson, read in connection with the 



