128 



Hereditary Diseases of Horses. 



above noticed, also constitutes a powerful predisposition to many 

 diseases. In scrofulous subjects sore shins often occur- — a com- 

 plaint common in many racing studs, appearing chiefly in young 

 and rapidly-growing animals, depending on the excessive exer- 

 tions to which they are subjected in training, consisting of inflam- 

 mation of the periosteum investing the cannon bones, especially 

 of the hind limbs, and, when neglected, often running on to caries 

 and necrosis. 



From their weak and unsound constitution, horses of a scro- 

 fulous diathesis are unusally prone to glanders and farcy — two 

 forms of a disease peculiar (at least as an original disease) to the 

 equine species. As has been already remarked, it is charac- 

 terised by a specific unhealthy inflammation, identical in all im- 

 portant characters with the syphilitic inflammation in man. 

 From the dire and loathsome nature of glanders, and the terror 

 in which it is held, animals affected by it are never used for 

 breeding, so that we have little opportunity of judging of its 

 hereditary nature. There is no evidence (so far as I know) which 

 proves it to be directly hereditary,* but there is no doubt that 

 the progeny of a glanderous horse would exhibit an unusually 

 strong tendency to the disease. Its ordinary predisposing causes 

 are, many of them, hereditary : it is very prone to attack animals 

 of a weak or vitiated constitution. It is emphatically the disease 

 which cuts off all horses that have had their vital energies re- 

 duced below the healthy standard, either by inherent or acquired 

 causes. Glanders is also sometimes caused by inoculation ; 

 is frequently produced in healthy subjects by mismanagement, 

 as by insufficient food, want of shelter, and overwork ; and often 

 supervenes on bad attacks of influenza, strangles, diabetes, and 

 other diseases which debilitate the system, or impair the integrity 

 of any of its more important parts. These causes appear to 

 possess the power of engendering in the constitution of the horse 

 a peculiar poison, which, as it reproduces itself, and spreads to 

 all parts of the body, gives rise to the characteristic symptoms of 

 glanders, causing, sooner or later, a breaking up of the system, 

 and a fatal prostration of the vital powers. This poison pro- 

 duces in the blood abnormal changes, which vitiate that fluid, and 

 unfit it for healthy nutrition. "j" From the irritant action of the 

 morbid fluids passing through them, the lymphatic glands and 



* Though I am not aware of any facts proving glanders to be congenital, yet I 

 think there is every probability that such is the case ; for it is notorious that 

 syphilis, the analogous disease in the human subject, is congenital, and often 

 appears at birth in the children of women affected by that disease. 



t A comparison of the two subjoined analyses "will show the great difference in 

 composition between the blood of healthy and of glanderous horses— a difference 



