34 DISEASES OF THE HORSE. 



The alterations in an inflamed tissue are first those of congestion, 

 distention of the blood vessels, and exudation oi the fluid of the blood 

 into the surrounding fibers, with, however, a more nearly complete 

 stagnation of the blood; fibrin, or lymph, a plastic substance, is 

 thrown out as well, and the cells, which we have seen to be living 

 organisms in themselves, no longer carried in the current of the 

 blood, migrate from the vessels and, finding proper nutriment, pro- 

 liferate or multiply with greater or lesser rapidity. The cells which 

 lie dormant in the meshes of the surrounding fibers are awakened 

 into activity by the nutritious lymph which surrounds them, and 

 they also multiply. 



Whether the cell in an inflamed part is the white ameboid cell of 

 the blood or the fixed connective tissue embedded in the fibers, it 

 multiplies in the same way. The nucleus in the center is divided into 

 two, and then each again into two, ad infinitum. If the process is 

 slow, each new cell may assimilate nourishment and become, like its 

 ancestor, an aid in the formation of new tissues; if, however, the 

 changing takes place rapidly, the brood of young cells have not time 

 to grow or use up the surrounding nourishment, and, but half devel- 

 oped, they die, and we then have destruction of tissue, and pus or 

 matter is formed, a material made up of the imperfect dead elements 

 and the broken-down tissue. Between the two there is an interme- 

 diate form, where we have imperfectly formed tissues, as in " proud 

 flesh," large, soft splints; fungous growths, greasy heels, and thrush. 



Whether the inflamed tissue is one like the skin, lungs, or intes- 

 tines, very loose in their texture, or a tendon or bone, dense in struc- 

 ture, and comparatively poor in blood vessels, the principle of the 

 process is the same. The effects, however, and the appearance may 

 be widely different. After a cut on the face or an exudation into the 

 lungs, the loose tissues and multiple vessels allow the proliferating 

 cells to obtain rich nourishment ; absorption can take place readily, 

 and the part regains its normal condition entirely, while a bruise at 

 the heel or at the withere finds a dense, inextensible tissue where the 

 multiplying elements and exuded fluids choke up all communication, 

 and the parts die (necrose) from want of blood and cause a serious 

 quittor, or fistula. 



This effect of structure of a part on the same process shows the 

 importance of a perfect knowledge in the study of a local trouble, and 

 the indispensable part which such knowledge plays in judging of the 

 gravity of an inflammatory disease, and in formulating a prognosis or 

 opinion of the final termination of it. It is this which allows the vet- 

 erinarian, through his knowledge of the intimate structure of a part 

 and the relations of its elements, to judge of the severity of a disease, 

 and to prescribe different modes of treatment in two animals for trou- 



