INFECTIOUS DISEASES OF CATTLE. 387 



In addition to these measures it is also necessary to guard against 

 the removal of animals from one stable to another, and the mixing of 

 herds upon common pastures or in the public highways. The object 

 must be to isolate every individual's cattle as completely as possible, or 

 otherwise a single affected animal may infect a dozen or more herds. 

 To prevent surreptitious sale or trading of cattle, each animal must 

 in some way be numbered and recorded in the books kept by the official 

 in charge of the district. In the work of the U. S. Department of Agri- 

 culture a numbered metal tag has been fastened to every animal's ear, 

 and index books have been so arranged that with a number given the 

 owner could be at once ascertained, or from the owner's name the cattle 

 for which he was responsible could be at once learned. In this way if 

 an animal was missing from a stable the fact became apparent at once, 

 or if one animal too many was found in a stable the number in its ear 

 would indicate where it came from. 



When pleuro-pneumonia is discovered by these means the entire 

 herd should be slaughtered as soon as the formalities of appraisement 

 can be arranged. In country districts the carcasses should be buried, 

 as it is generally impracticable to dispose of them in any other way. 

 In city districts the animals may be taken to a slaughter-house, with 

 such precautions as are possible to prevent dissemination of the con- 

 tagion. The animals should be slaughtered under the supervision of 

 an inspector. The healthy carcasses may be utilized for food, but the 

 blood, eutrailsj and all diseased carcasses should be heated to a tem- 

 perature equal to or above boiling water, and then used for the manu- 

 facture of fertilizers. 



The disinfection of premises should be thorough and should be car- 

 ried out by a trained corps of men employed- for that purpose. The 

 floors of stables should be removed, the accumulations removed from 

 beneath them, the contents of hay-lofts should be destroyed, and the 

 woodwork and soil beneatli the stables should be thoroughly drenched 

 with a solution of bichloride of mercury, one part to two thousand of 

 water. After the flooring is replaced the woodwork should be coated 

 with lime wash, containing one-fourth i>ound of chloride of lime to the 

 gallon of mixture. 



Usually in these cases the owners are dc]>cndcnt upon their herd of 

 cows for their living, and, consequently, it is difficult or impossible to 

 hold the stables vacant for any considerable period. In a majority of 

 instances cattle maybe at once admitted to stables so disinfected, with- 

 out the reappearance of the disease. Occasionally, however, it will 

 reappear without apparent cause. For this reason the inspection and 

 other measures must be maintained in the infected district for six 

 months or a year after the last case of disease has been disposed of. 



Many people have objected to the slaughter of diseased and exjiosed 

 animals as an unscientific and expensive method of eradicating this 



