Nu. 6. DEPARTMENT (JF AGRICULTURE. 67;t 



1)K. PEAKSON: Wliciv it i« known that ;i dog has been bitU-ii 

 it may be destroyed under the act of lS'o2. Where an allidavit has 

 been made before a juagistrate, making it known that a dog has 

 been bitten, the magistrate is required to kill the dog. 



MR. CREASY: How about counties that have special dog laws? 



DK. TEARSON: It is the same in all counties, except where 

 special dog laws have been passed since the act of 1832, but almost 

 all the dog laws were enacted after that law. So that it applies 

 to most of the counties. 



The other subject of legislation to which 1 desire to call to your 

 attention is one that provides for the investigation of the diseases 

 of animals as well as for the investigation of tuberculosis. I made 

 a report some years ago with reference to the vaccination of cattle 

 against tuberculosis. The State of Pennsylvania has the reputation 

 of having made the first experiments in this direction and, as far as 

 I know, the first experiments made on cattle anywhere in the world. 

 This has recently been going on, to some extent, in Germany and 

 in AYashington it is being investigated. The vaccination of cattle 

 for tuberculosis depends on the principle that after an animal is 

 affected in a mild form, and is inoculated, it has increased re 

 sistance to that disease and so it is put through that principle in 

 order to counteract the disease. The test of the method has con- 

 sisted in vaccinating cattle, and exposing them, by direct inoculation, 

 by injecting germs of tuberculosis into the windpipe or causing them 

 to inhale them or eat them and sometimes the experiment has been 

 to expose the unvaccinated animals in the same way and the result 

 has been that the animals not inoculated have contracted the dis- 

 ease, where vaccinated animals were protected against the disease. 

 In many instances they have been protected wholly from the dis- 

 ease. In other cases they have not been protected wholly; there 

 was some effect, showing that the vaccination was not suflScient in 

 those cases to wholly protect them. That brings us to the point, 

 that the degree of protection depends on the number of vaccina- 

 tions. It is not a single vaccination, unfortunately. If the ani- 

 mal was proof against it with one vaccination it would be very 

 easy of solution. The more often the vaccination is repeated the 

 higher degree of resistance is afforded. The experiments that are 

 now being made are with cattle kept on a farm for the purpose of 

 making these tests. There are about eighty cattle on the farm in 

 Delaware county. 



A Member: With vaccination would if continue to be proof 

 against taking tuberculosis throughout the life of the animal? 



DR. PEARSON: \Ye have animals now vaccinated two years ago. 



