270 MISSOURI AGRICULTURAL REPORT. 



likely to contract the disease because tuberculosis germs escape from the 

 body through the udder with the milk. The mucus coughed up by a cow 

 and which lodges upon the manger or walls of the enclosure mav be- 

 come dried into a powder and be blown about in the air, and in this way 

 breathed into the lungs by healthy cattle, there to set up the disease. 



This disease develops very slowly, it requiring weeks and months 

 for it to reach a stage at which any symptoms are produced recognizable 

 by the ordinary observer. When the disease is contracted by the animal 

 breathing the germs into the lungs, the first symptom is a cough which 

 gradually becomes more and more frequent. Coughing spells are brought 

 on by exertion, such as getting up after having lain for a time, running, 

 or by drinking freelv of cold water. If the infection occurred through 

 swallowing the virus, often the first symptom is that of indigestion with 

 bloating, and diarrhoea alternating with constipation. After the dis- 

 ease has progressed farther and interferes with the functions of one or 

 more vital organs the animal begins to lose in flesh and shrink in milk, 

 if giving milk, and all the symptoms increase in severity until the ani- 

 mal is destroyed or dies of the disease. No matter in what organ the 

 disease first starts, it will ultimately spread to all parts of the body. 



When it develops in the udder, it is recognized by the formation of 

 rounded masses here and there in one or more quarters. Sometimes a 

 number of such masses, varying in size from a hazelnut to a walnut, are 

 so close together as to appear, when handled, as one nodular painless 

 mass. The quarters in which large masses develop usually give a thin 

 watery milk which is very noticeable when compared with that of the 

 other quarters. 



It behooves every dairyman to be alert and not permit any diseased 

 animal to become a part of his herd. When such a one is found he 

 should dispose of it and protect his herd from contamination. The cow 

 which has a persistent cough or diarrhoea, or continues to become un- 

 thrifty under the same treatment that others maintained a fair condition, 

 or one in which nodular masses develop in the udder should be at once 

 separated from the herd. If it does not seem desirable to dispose of that 

 animal at once, it should be kept apart from the others and watched for 

 further developments. When a herd once becomes infected with tuber- 

 culosis, it will not long remain a profitable herd. The loss from death 

 and from shrinkage in quantity of milk and physical condition of the 

 animals is quite sure to take away the profits. 



There is yet another factor to be considered, the milk from a tuber- 

 culous cow when fed to pigs will give the disease to these animals. It 

 is customary among dairymen and feeders of cattle to haul the carcass 

 of a cow or steer that dies to a place where the swine may feed upon it, 



