78 DISEASE AMONG SWINE AND OTHKR DOMESTIC ANIMALS. 



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ica. Its spread was imdoubtetlly due to couta<;ion, for it is not at all probable that the 

 disease orij^inatod spontaiieonHly outside of Central Europe. It isa specific disease pe- 

 culiar to bovine animals, for other sjiecies are never affected with it. It is always sub- 

 acute or chronic in character; usually occurs as an e])izooly or enzooty, and sjjreads 

 easily and rapidly. 



As the term indicates, the lunf/n and the pleura are the seat of the disease. It is not 

 considered an imllanuuatory disease, and so far as local lesions are concerned, consists 

 in an exudation of lymph into the connective tissue of the lunj^s, with effusion and 

 exudation into the pleural cavities. The disease may be.limited to one lnn<? or it may 

 affect both, while occasionally the pericardium is implicated. One attack usually con- 

 fers immunity from subsequent ones. During its course the disease generates a spe- 

 cific virus capable of inoculating healthy animals of the same species with the same 

 disease. liy some few authorities it is believed that the disease can be generated by 

 improper dietetic nuiasures in conjunction with certain other influences, as excessive 

 milking, and hot, illy- ventilated stal)lcs, but there is no positive proof to support this 

 belief, although it is to bo noted that the outbreaks in New Jersey in 1873-74 and in 

 1877 were almost exclusively confined to cattle fed on Ijeer-grains, which were kept in 

 close stables, and gave largo quantities of milk. The disease was brought to this 

 country in 1849, and has prevailed to a greater or less extent in different localities ever 

 since. 



The period of incubation is reckoned at from twelve to sixty days, and the symptoms 

 during this time are, as a rule, so slight as to receive little or no attention from owners 

 or attendants. A rise of the bodily temperature is the first indication of the disea.se, 

 and can be detected with the thermometer alone. Healthy animals have a tempera- 

 ture of lUO^ F., or a little less, so that a rise above this in an infected district would 

 render all animals so affected liable to suspicion, for in those where the thermometer 

 registers 10"2'^ F. or moi-e the disease can almost positively l)e said to exist. The first 

 symptom to gain the attention is mostly a short, dry, husky cough, of a peculiar char- 

 acter, and is first heard in the early morning, or while the animal is drinking. At the 

 same time the ap]»etite will beobserved to fall off a little, and ruminaticm bolessactive 

 than common. The respirations are more rapid than normal, an<l may reach twenty, 

 twenty-five, or thirty per minute, instead of about fourteen. Usually every respiration 

 is accompanied with a low grunt or slight moan. The cough is growing more frequent, 

 harsh, aiul painful ; the back is slightly arched; the coat looks dead, and feels rough 

 and harsh, while in some places it is erect ; pressure along the back, especially in the 

 neighborhood of the loins and in the spaces between the ribs, causes pain and flinching. 

 As the appetite falls off the secretion of milk diminishes, until it is finally completely 

 suppressed. The patient generally rapidly runs down in flesh, the surface temperature 

 varies, the extremities being cold at one time and hot at another ; sometimes but not 

 always a slight discharge takes place from the nostrils, and the pulse becomes quite 

 rapid. The lungs at this time are undergoing changes, easily detected by the expert ; 

 the air-cells aduut but a limited quantity of air to the affected jlart ; the intestinal tis- 

 sue is filliugup with lymph, and the pleura is undergoing the changes seen in this disease, 

 presenting symptoms to be detected only by the practiced ear, as loss of the respiratory 

 murmur, the presence of the different rahls and the friction murmur of i^leurisy, with 

 finally the absence of any sound at all as the lungs become hepatized in the second 

 stage, or the one of marked symptoms. In this stage the temperature increases and the 

 pulse runs np to 60 or 70, and sometimes to 90, beats per minute. Examination of the 

 heart will show it to be laboring hard to send the blood to the diseased lungs in suffi- 

 cient quantity for the system ; the extremities are cold ; the front legs apart to facilitate 

 respiration, which is beconung more and more rapid and difficult ; the appetite is en- 

 tirely lost ; the secretion of milk has ceased ; the feces are hard and dark colored ; the 

 urine is scanty and high colored ; drinking causes hard and painful coughing. The 

 animal almost refuses to move, seldom lies down, and stands with distended nostrils, 

 moaning at every respiration, while from the eyes and nose is dischai-ged a thickish, 

 purulent fluid, and the breath is hot and foetid. These symptoms daily grow worse as 

 the disease encroaches on the previously healthy lung-tissue ; breathing is effected with 

 the greatest difficulty ; the pulse is so weak and small as hardly, to be felt ; the skin 

 clings to the bones; dropsy beneath the chest takes place; the animal becomes almost 

 unconscious of all surroundings, and groans and grinds the teeth ; the abdomen fills 

 with gas ; diarrhea sets in, and death speedily closes the scene. 



This is the usual course of a typical case where the disease runs through both stages 

 and terminates fatally. In many instances there are variations from this general course, 

 as where a fatal diarrhea sets in early or some other complication occurs which carries 

 the patient off. (An interesting complication occurred in a case at North Branch, N. 

 J^ in 1874, where the lungs filled up rapidly and the pulmonary artery was ruptured.) 

 Bat these variations are important only to the student of special pathology. 



Regarding the course and termination of this disease, it is to be noted that it runs a 

 more rapid course in young, vigorous animals than in any others ; also that a short 

 period of incubation is almost always followed by a rapid siibseciuent coarse. At times 



