THEIR CAUSES, NATURE, AND PREVENTION. 193 



either to a depraved condition of the blood as the result of injudi- 

 cious management, to irritation of the stomach and bowels, to 

 a microscopic parasite acting locally, or to some parasitic product, 

 such as ergot, acting systemically. 



Like eczema it is ordinarily of a mild character, but if neglected 

 it may lead to deep-seated and destructive inflammation of the 

 involved organs ; ultimately producing death by exhaustion or by 

 blood poisoning. 



The disease makes its appearance at the outset as a painful 

 circumscribed swelling on the coronet or lip, or both. In due 

 course ulceration of the skin results and an angry-looking 

 sore, associated with considerable thickeniug of the surrounding 

 tissues, is formed. If properly treated this sore quickly heals, 

 but if irritated by dirt or other material it takes on un- 

 healthy action, spreads to surrounding tissues, and becomes 

 very intractable. 



The measures recommended in reference to eczema should be 

 also adopted in dealing with this affection. 



Of the extraordinary diseases believed to be due to fission or 

 cleft fungi, we have two forms, viz., those which are non-con- 

 tagious and those which are contagious. The former are 

 mainly the class of disease marked by putrefaction and blood 

 poisoning (septicaemia), and which have already been largely 

 alluded to. Contagious diseases proper, peculiar to sheep in 

 this country, are fortunately few. So far as we know, they are 

 largely exempt from consumption (tuberculosis), from glanders 

 and from pleuro-pneumonia; they are, however, highly susceptible, 

 though only secondarily, to foot-and-mouth disease, to malig- 

 nant catarrh, to dysentery and to anthrax. 



Malignant catarrh is often very destructive to hill sheep, 

 especially in bad seasons, and it is very intractable. Beginning, 

 apparently, as a simple cold, it is quickly followed by destruc- 

 tive inflammation of the lining of the nostrils and ulceration 

 which is again succeeded by abscesses in the glands of the face 

 and throat, and in the lungs ; and, if the animal lives long 

 enough, by emaciation and diarrhoea. The particular form of 

 fungi or germs to which it is due have not yet been recognised, 

 but that it is fungoid in origin is almost a certainty, and it is 

 probable that the fungus belongs to the spherical form of bac- 

 teria — that it is a micrococcus. 



Dysentery appears usually amongst sheep in hot summer 

 weather with excess of moisture, and on rank pastures or on 

 overstocked and consequently befouled pastures ; and in droughty 

 summers on lands upon which there are stagnant pools of 

 water with rank growth of grass around their borders. Even in 

 the dysentery of man the exact nature of the disease has not 

 been determined but it is generally thought that it is due to a 



VOL, XX. N 



