INFECTION AND CONTAGION. 135 



3rd. Glanders and Farcy are different forms of the same disease. In 

 common with man's other specific disease it is impossible to assign its 

 origin. It is highly contagious. (See Chapter 29.) 



4th. Epizootics, such as influenza and low fever. Causes. Diseases 

 of this class are generally admitted to be of a specific, contagious, or in- 

 fectious character, and are popularly supposed to be in a great measure 

 influenced by atmospheric peculiarities, but the precise nature of this is 

 not well understood. This much, however, is certain, that whilst epi- 

 zootics run almost periodically and with great severity through badly 

 ventilated, ill drained, dirty, badly regulated stables, they seldom 

 seriously affect those where proper sanitary arrangements are enforced 

 and where the stable management is good. 



5th. Diseases of the eyes. Common ophthalmia generally arises from 

 accidents. Occasionally it is due to an extension to the eye of inflamma- 

 tion already existing in the mucous membrane of the nose. True, or as it 

 is usually termed, Specific ophthalmia arises from constitutional causes, 

 for a detail of which the reader is referred to Chapter 57, on the Eye ; 

 and sometimes from hereditary predisposition. 



6th. Diseases of the skin, such as mange and ringworm, are generally 

 connected with bad grooming or bad forage, and sometimes with the use 

 of barley straw for bedding. Some skin diseases are occasionally propa- 

 gated by contagion. 



7th. Cracked heels and grease and canker nearly invariably proceed 

 from neglect or bad management. No doubt certain horses are more 

 predisposed than others to such affections ; but these diseases, we be- 

 lieve, will never appear where the stable management is really good. 

 Thrush also is usually a disease of neglect. 



8th. Diseases of the feet, such as corns, sandcrack and quittor. Causes. 

 Bad shoeing and neglect. 



9th. Sore backs and broken knees. Causes. Bad saddling and bad 

 riding, and also as regards broken knees, bad shoeing, defective action 

 and accidents. 



10th. Bites, kicks and wounds. Causes. Carelessness of servants and 

 bad stable gear. 



llth. Sprains and diseases of joints. Causes. Severe work or work 

 for which the animal is physically unfit, or for which he has been insuffi- 

 ciently prepared ; and also accidents. 



12th. Strangles. Strangles is a specific disease. At some time or 

 other it appears in most horses ; but its development at any particular 

 time appears to be dependent in some cases on atmosphere changes. 



13th. Accidents. Causes may, as a general rule, be summed up under 

 the heads of carelessness and bad management. Some few accidents, 

 however, are confessedly unavoidable. 



14th. Laminitis, Weed and some other diseases, though local in their 

 development, usually proceed from constitutional disturbance. Over- 

 feeding and want of exercise in some cases, and the reverse conditions, 

 such as over-severity of work and bad feeding in other cases, are the 

 common causes of the derangement of the general health. 



