110 ANNUAL REPORT OF THE Off. Doc. 



If, under such circumstances, the young and as yet uninfected cattle in the 

 held can be protected from infection for a couple of years, this allows time to 

 re-organize the herd, to place buildings in sanitary condition and to bring 

 the young cattle into profit. "Vaccination would, of course, be very much more 

 useful if its effects were of greater duration. If an animal could be immunized 

 for life against tuberculosis it would be most useful. Von Behring and his corn- 

 mercial agents originally claimed, in advance of sufficient trial, that his 

 method would immunize cattle against tuberculosis for life. It has since been 

 found that these claims are without warrant. Hutyra has shown that animals 

 that he immunized by the Von Behring method with "bovovaccine," lost their 

 immunity at the expiration of about twelve months or less. 'Since artificial im- 

 munity will not last for life we need a method to restore or to renew the re- 

 sistance of an animal that has been once vaccinated and that is gradually out- 

 growing its resistance to tuberculosis. Since the vaccine that is used contains 

 the living virus, it is considered undesirable to use it on cows in milk or on 

 heifers or cows that within a short time will be in milk. It has not been dem- 

 onstrated that the tuberculosis vaccine is eliminated through the udder of a 

 cow in lactation but, nevertlieless, tO' be on the safe side, such a vaccine as 

 is now commonly in use should not be used on cows that are in milk or cattle 

 that will furnish milk within three months of the last vaccination. In fact, to 

 be entirely on the safe side, and beyond any possibility of criticism, it is our 

 practice to restrict vaccination to young cattle and to heifers that have not yet 

 been bred. We need now to develop a system of re-vaccination that does not 

 involve the use of a virus that is at all pathogenic for man. The experiments 

 that we have made do not encourage the belief that immunity may be restored 

 by the use of dead bacilli, extracts of tubercle bacilli or any kind of non- 

 vital material. The most encouraging outlook is found in the use of living, 

 a virulent tubercle bacilli. It is necessary that extended experiments shall be 

 made along this line. The results that have already been shown in relation to 

 the vaccination of cattle against tuberculosis are of much practical value and 

 enourage the hope that the method may still further be improved and its value 

 increased. 



There have been requests from some of the public institutions of the State, as 

 insane hospitals, where herds of cattle are maintained, that the State Livestock 

 Sanitary Board shall, through its agents, take charge of the hygiene of the herd 

 and be responsible for the prevention of infectious diseases. It has never been 

 possible for this office to assume any such responsibility for the reason that our 

 staff and our funds are entirely too limited. If it is necessary to select between 

 the use of the funds of the State Livestock Sanitary Board for the protection 

 of a farmer's herd or of a herd belonging to the State, the benefit of the de- 

 cision would be given the private farmer, on the basis that the institutions in 

 charge of herds are supplied with State funds for the care and protection of 

 such herds, while the private farmer is without public relief, excepting as it 

 may be afforded through the State Livestock Sanitary Board. This ofHce has, 

 however, always been ready to respond so far as possible to calls for assistance 

 from such institutions and where it has appeared that there was reason for an 

 Inspection at the expense of the State such an inspection lias always been made, 

 and the institution has been supplied with such help and information as may 

 have been appropriate for the purpose of controlling infectious diseases of ani- 

 mals and of preventing subsequent loss. LTnder these circumstances, the herd 

 of the State Lunatic Hospital at Harrisburg was tested in 1897. It was found 

 that the herd was practically saturated with tuberculosis. The herd was dis- 

 posed of by slaughter and a new herd was organized; the premises were cleaned 

 and disinfected and the new herd was subsequently retested and was left, in 

 1900, under healthy conditions without any evidence of tuberculosis. During the 

 latter part of 1906, a request was again received from the superintendent of the 

 State Lunatic Hospital for an inspection of the herd. The inspection was made 

 by an agent of the Board, Dr. Enoch Barnett. It was found that a number of 

 cattle showed well marked physical signs of advanced or general tuberculosis 

 denoting long existing disease, and upon the tuberculin test it was discovered 

 that m.ost of the cattle in the herd were infected in some degree. Further inves- 

 tigation showed that evidence of tuberculosis had existed in this herd for sev- 

 eral years and that a number of tuberculous cows had been removed from this 

 herd from time to time for as long as three years. Of course it is well known 

 that a cow is likely to excrete tubercle bacilli for a long time, possibly for 

 months, before the disease becomes so advanced that the constitution of the 

 cow is so broken down as to give rise to marked, physical signs of disease. 

 Hence, it is clear that this herd has been exposed to tuberculosis to an unknown 

 but probably to a considerable extent, for as long as three years prior to the 

 report received in December 1906. This case is here referred to for the purpose 

 of emphasizing the necessity for extreme watchfulness and care of such an 

 important herd (as indeed, of any herd) and the importance of reporting the 

 herd for test immediately when the first animal with tuberculosis is found. In 

 this case the disease was permitted to spread for as long as three years before 

 the report was made and during this time the herd was being riddled with the 

 disease and ruined. Large experience justifies the statement that it is very 

 probable that if this herd had been tested with tuberculin when the first affect- 

 ed animal was found, it would have been discovered that the infection was not 

 widespread and it could have been extirpated without serious logs, 



