No. 6. DEPARTMENT OF AGRICULTURE. 125 



From our present knowledge of this subject there appears to be 

 every reason to believe that the oxygen treatment is the best treat- 

 ment that has thus far been devised, and if subsequent results with 

 it are as good as those already reported, we may expect to save 

 from 9U to JJ5 per cent, of all cases of parturient paresis, and by the 

 use of this treatment, the lives of at least 5U,0UU cows should be 

 saved every year. These are the best cows used for dairy pui*- 

 poses, and if they have an average value of |50, the total amounts to 

 $2,500,UUU. It is believed that this amount represents conserva- 

 tively the saving to the country that will come from the general 

 use of the knowledge or the treatment of parturient paresis that 

 has been developed in the last decade by veterinarians. It is a 

 striking illustration of the value of veterinary research to animal 

 husbandry and national economy. 



Tuberculosis of Cattle. — Tuberculosis prevails in practically all 

 parts of Pennsylvania, but it is much more prevalent in some dis- 

 tricts than in others. In some of the mountainous counties, no 

 cases of tuberculosis have been found. In a number of other coun- 

 ties the disease is exceedingly rare, but in the oldest settled parts 

 of the State, where the dairy industry has reached its highest de- 

 velopment, and where the herds are recruited by purchase, there is 

 found the maximum prevalence of this disease. Attention has been 

 called in previous reports to the factors that govern the distribution 

 of tuberculosis. This disease is more prevalent in some places 

 than in others, because, having been introduced, it has been per- 

 mitted to spread from animal to animal, and from herd to herd 

 until, at length, it has attained a very wide distribution. Naturally, 

 the disease was first introduced into the districts importing the 

 greatest number of cows. Such districts were constantly more 

 heavily seeded with tuberculosis through the continued importa- 

 tion of diseased animals. It is possible to ascertain definitely that 

 tuberculosis is comparatively a recent disease in almost all of 

 even the oldest dairy sections. While reports of other diseases 

 came down to us from the early days of the republic, there are few 

 reports of disease of cattle that may be recognized as referring to 

 tuberculosis. Such reports are rare and show that this disease 

 was so infrequent as to be of very little importance. As tubercu- 

 losis was not known to be contagious until after it had spread con 

 tagion to a tremendous extent, no effective precautions were taken 

 or could be taken to restrict its progress. 



A great many things occurred in the early ''boom" days of several 

 breeds of cattle that helped to establish tuberculosis in maoy herds 

 and to scatter it OA^er wide areas. It happened, shortly after the 

 Civil War, that several breeds of cattle were exploited in a way 

 that while it was, no doubt, beneficial in some respects, still it had 



