Lung Plague of Cattle. 657 



the rib, or establishing permanent adhesions. The amount of 

 pleural effusion may be about two gallons in bad cases, and like 

 the invasion is either unilateral or bilateral. The pericardium is 

 usually more or less involved in pleuritic cases. 



The larger bronchia sometimes contain false membranes. 



The bronchial, prepectoral and mediastinal lymph glands are 

 often enlarged, congested and infiltrated with an abundant 

 exudate. 



Similar infiltration of the lymph glands of the pharynx, mesen- 

 teries, sublumbar region and groin are described, together with 

 h5^ertrophy and congestion of the intestinal follicles, and conges- 

 tion of the muscles and inter- muscular tissue, of the articular and 

 tendinous synovial sacs, and even of meninges of the brain 

 and cord. I know of no facts to show that these conditions result 

 from anything else than the toxins and the general constitutional 

 disorder. The indications are that the microbes are speedily 

 destroyed in the circulating blood, and intravenous injections and 

 caudal inoculations alike fail to cause the characteristic lesions in 

 the lung, their favorite point of casual election. 



Incubation. This usually lasts from 6 to 30 days, being greatly 

 abridged by hot weather and often prolonged in the cold. Dela- 

 motte claims to have seen it extended to 5 months, and in one case 

 a calf turned out on Montauk Point, t,. I., from an infected place 

 was noticed ill on the 104th day. Australia, South Africa and 

 Norway were each infected by cattle that had been three months 

 out of the native infected land. I have seen cattle pass three 

 or four months after purchase in an unhealthy condition, yet with- 

 out cough or other recognized diagnostic symptom and then come 

 down withilung plague. Such doubtless explain the alleged pro- 

 tracted incubations, the system has been invaded, ill health ensues, 

 but the lungs are only slightly affected for a length of time. In 

 other cases one animal in a herd has had a mild attack, which 

 escaped notice, and it was only later that the disease was recog- 

 nized in a second victim, infected from this first. 



The bearing of this on imported animals is evident. An ani- 

 mal imported alone should be kept under surveillance for a month 

 or two after quarantine, while in any considerable herd the disease 

 would certainly manifest itself during the prescribed three months 

 detention. 

 42 



