474 MILK 



the virus, but it is probably not dangerous, since the virus is not 

 absorbed through uninjured mucous membranes of the mouth or 

 the digestive tract. 



Actinomycosis sometimes attacks the udder, and the appear- 

 ance then resembles, and has been mistaken for, tuberculosis. 

 Spores of actinomyces are widely distributed on grain, hay, straw, 

 soil, manure, etc., and can easily gain access to milk. They are 

 usually not infectious for man unless they locate in some injured 

 part of the system. There is practically no danger from this 

 disease if the milk contains spores. In fact, no case has ever been 

 recorded. However, as a precaution, milk should be condemned 

 if derived from actinomycotic animals. 



Botryomycosis. — This disease is very rare in the udder, 

 but may endanger the milk. Therefore such milk should be 

 excluded. 



Cowpox is sometimes transferred to the udder from calves, 

 which are used for the preparation of smallpox vaccine. It 

 spreads rapidly through a herd by being carried from cow to cow 

 by the milker's hand. Pustules and ulcers form on the teats. 

 Milk infected with the virus is dangerous, especially for children. 

 An infection of the digestive tract is produced. Dean and Todd 

 have isolated a bacillus from cowpox pustules which seems iden- 

 tical with the diphtheria bacillus. Diphtheria bacilh may be 

 communicated to infected teats from the hands of diphtheria 

 carriers. The milk from cows with pustules or ulcers on the 

 teats should, therefore, be considered suspicious and be excluded 

 from the supply. 



Milk-sickness is a disease peculiar to the United States west 

 of the Alleghenies. It is also known as "trembles," "slows," and 

 "staggers." It is believed to have been more common formerly 

 than at present. It is called milk -sickness because it seems to 

 follow ingestion of milk or milk products from infected cattle. 

 The meat of cattle infected with the disease is also infectious for 

 man. Its distribution is confined to limited localities. Cattle 

 infected with the virus become weak, are easily tired, fall on their 

 knees, and tremble violently. The temperature of such cattle is 

 normal or subnormal. The cause of the disease, according to 

 Jordan and Harris, is a spore-bearing bacillus which grows well 

 on artificial media. This organism was named Bacillus lacti- 

 morbi. Besides cattle; the disease occurs in horses, sheep, goats, 

 dogs, and perhaps in hogs. Some of the symptoms have been 

 reproduced in calves, dogs, and cats by injection of cultures of 

 Bacillus lactimorbi. 



The virus persists in nature for a long time. In soil it may 

 remain for at least fifty to sixty years if the land is left wild. 



