244 DISEASES OF THE HORSE. 



the body, wliicli burst find form scabs. On rubbing off these 

 scabs, there appears a white spot covered by a thin acrid fluid, 

 which contains the source of infection. These scabs, at first, 

 are confined to one or two spots, but, if not removed, gradually 

 spread over the body. The parts most frequently attacked are 

 the withers, the roots of the mane and tail, and the rump or 

 buttocks. The animal, from the irritation received, rubs off 

 the scab, and the acrid fluid spreads and forms a larger scab, 

 and thus deprives the affected part of hair. As the disease pro- 

 ceeds the greater part of the body becomes affected, and the 

 animal presents a miserable appearance. The constant irritation 

 allows him no I'est ; he rapidly loses flesh, and the skin, particu- 

 larly that of the neck, becomes considerably thickened and 

 wrinkled. 



When the disease has existed some time, its appearances are 

 too striking to be for a moment mistaken ; but in the earlier 

 stages it may, in a great measure, be detected by rubbing the 

 animal with a stick ; when he immediately expresses his pleasure 

 by elevating and moving quickly the upper lip, and extending 

 the head in a peculiar manner. It is likewise by the diminution 

 of this symptom that we are enabled to ascertain the progress of 

 the disease towards a cure. 



The nature of this disease has been found, by microscopic 

 observation, to be owing to the presence of minute insects which 

 have been denominated acari. Similar insects have been found 

 in the itch of the human subject, but of a different species. It 

 has been found that mano-e can be communicated to the human 

 subject and to other animals from the horse, although by no 

 means so readily as between animals of the same species. A 

 curious experiment was tried by a German student, a few years 

 since, by taking eight horse acari, of both sexes, and confining 

 them to his arm by means of a plaster. In a few minutes they 

 produced a great itching, which continued five days ; but the 

 part afterwards got well of its own accord. After the lapse of 

 thirty-two hours, four of the insects had disappeared ; but there 

 were found several eggs and small passages under the skin made 

 by the insect, — in forming which, in all probability, the itching 

 was produced. 



This disease is most frequently produced by contagion, either 

 by direct contact with a mangy horse, or by rubbing on the 

 spot where a diseased horse has been rubbing himself previously. 

 Poverty, also, not unfrcquently produces it ; and thus it is often 

 found on poor commons or moors, where, however, it quickly 

 spreads from one horse to another by contagion. When it gets 

 into a large stable of horses, it is difficult to eradicate it, in con- 

 sequence of its infectious character, and the greater portion of 

 the stud will probably become affected. 



