LUNG PLAGUE OF CATTLE 413 



only those showing clinical symptoms are disposed of, no 

 thorough disinfection practised and later new cattle brought 

 in to replenish the herd, 



Treatment. — Palliative measures are rarely successful and 

 generally lead to the further spread of the disease. To wipe 

 out lung plague all sick and exposed animals should be 

 slaughtered and the premises they occupied (barns, shed, etc.) 

 thoroughly disinfected. Once this drastic method is enforced 

 the disease is soon entirely eradicated. In the United States 

 and in other countries where it no longer exists, no cattle 

 should be imported from an infected country without passing 

 through a strict (ninety-day) quarantine. 



Preventive Inoculation. — In countries, as in South Africa, 

 where it is impossible to enforce drastic measures of eradica- 

 tion or even efficient quarantine, preventive inoculation 

 against limg plague of cattle has been practised with con- 

 siderable success. Among the difPerent methods employed 

 the following are described briefly: 



(a) Nocard Method. — Nocard employed living cultures of 

 the causal organism which were injected subcutaneously in 

 the dorsal aspect of the tail three or four inches from the tip. 

 One to four weeks later the animal reacts with symptoms of 

 slight fever, increased respirations and the formation of an 

 inflammatory swelling about the size of a hen's egg which 

 appears at the point of inoculation. Of nearly one thousand 

 cattle so inoculated none died and only three suffered loss of 

 the end of the tail. 



{by Pasteur Method. — The material for inoculation is 

 obtained from a local subcutaneous swelling, produced 

 artificially by injection of the yellow, fibrinous exudate from 

 the interlobular connective tissue of the lun^ of a natural 

 case. This material is injected into a healthy three- or four- 

 months-old calf in the dewlap or behind the shoulder. From 

 the resulting swelling the "lymph" is collected after the calf 

 has been kUled. A few drops are injected under the tail tip. 

 This method has not proved very successful as the virulency 

 of the "lymph" becomes too attenuated to produce the 

 desired immunity in all cases. A modification of this method 



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