CONTAGIOUS DISEASES OP DOMESTICATED ANIMALS. 443 



animal. The nostrils and even the comers of the month are strongly retxactocl. The 

 patient stands most of its time, and in some cases without intermission, its fore legs 

 set apart, its elbo-n-s turned oirt, and the shoulder-blades and arm-bones rapidly los- 

 ing their covering of flesh, standing out from the sides of the chest so that their out- 

 lines can be plainly seen. The head is extended on the neck, the eyes prominent and 

 glassy, the muzzle dry, a clear or frothy liquid distils from the nose aud mouth, the 

 back is slightly raised, and this, together -with the spaces between the ribs and the 

 region of the breast-bone, are very sensitive to xiinching : the secretion of milk is en- 

 tirely arrested, the skin becomes harsh, tightly adherent to the parts beneath, and 

 covered with scurf, and the arrest of digestion is shown by the entire want of ap- 

 petite and rumination, the severe or fatal tympanies (bloating), and later by a profuse 

 watery diarrhea in which the food is passed in an undigested condition. If the in- 

 fusion into the lungs or chest is very extensive, the pallorof the mouth, eyelids, vulva, 

 and skin betrays the weak, bloodless condition. The tongue is furred, and the breath 

 of a heavy, feverish, mawkieh odor, bnt rarely fetid. Abortion is a common result 

 in pregnant cows. 



During the summer the disease shows its greatest violence, and it is 

 then that its mortality is not only high but early. The great prostra- 

 tion attendant on the enormous effusion into the organs of the chest, 

 the impairment of breathing, and the impairment or suspension of the 

 vital functions in general, causes death in a very fe^w days. In other 

 cases the animals dijp early from distention of the paunch with gas, while 

 in still others the profuse scouring helps to speedily wear out the vital 

 powers. In certain severe cases the rapid loss of flesh is surprising. 

 Dr. Law says that in such cases a loss of one-third of the weight in a 

 single week is by no means uncommon, and even one-half may be parted 

 with in the same length of time in extreme cases. In fatal cases all 

 symptoms become more intense for several weeks, the pulse gradually 

 becomes small, weak, and accelerated, and iinally imperceptible ; the 

 breathing becomes rapid and difficult, the mucous membranes of the 

 mouth, eyes, &c., become j)ale and bloodless, emaciation goes on with 

 active strides, and death ensues in Irom two to six weeks. Sometimes, 

 in cold and dry weather, a portion of dead lung may remain encysted 

 in the chest, submitting to slow liquefaction aud removal, and such ani- 

 mals will go on for mouths doing badly, at last to sink into such a state 

 of debility that death ensues from exhaustion and weakness. In stdl 

 other cases the retention of such diseased masses, and the consequent 

 debility, determines the appearance of tuberculosis, from which the ani- 

 mal dies. Purulent infection and rupture of abscesses into the chest are 

 also causes of death, but the author states that no such cases have come 

 under his observation. 



Dr. Law gives the following description of the ^ost-morlem appear- 

 ances : 



If the disease is seen in its earliest stages, the changes are altogether confined to the 

 tissue of the lung. From the examination of the lungs of several hundred diseased 

 animals, I can confidently affirm that the implication of the serous covering of the 

 lung (pleura) is a secondary result. In all the most recent cases we find the lung sub- 

 stance involved aud the pleura sound, while in no one instance has the pleura been 

 found diseased to the exclusion of the lung tissue, or without an amount and charac- 

 ter of lung disease which implied priority of occurrence for that. Yet, in all violent 

 attacks the disease will have proceeded far enough to secure implication of the pleura 

 as well, and hence we may describe the changes in the order in which they are usually 

 seen when the chest is opened. Tbe cavity of the chest usually contains a quantity 

 of liquid varying from one or two pints to several gallons, sometimes yellowish, clear, 

 and transparent, at others slightly greenish, brownish-white, and opaque, or even ex- 

 ceptionally slightly colored with blood. This effusion contains cell-forms and gran- 

 ules, and gelatinizes more or less perfectly when exposed to the air. 



On the surface of the diseased lung, and, to a less extent, on the inner side of the 

 ribs, is a fibrinous deposit (false membrane), varying from the merest rough pellicle 

 to a mass of half an inch in thickness, and, in the worst cases, firmly binding the en- 

 tire lung to the inside of the chest and to the diaphram. These false membranes are 

 usually of aox opaque white, though sometimes tinged with yellow, and, ia the deeper 



