20 DISEASES OF CATTLE. 



desired, however, to examine the molar teeth with the fingers, so as to 

 obtain a more precise idea of their condition, an instrument like the ball- 

 ing-iron which is used for the horse should be introduced into the mouth? 

 so as to separate the jaws and keep them apart while the examina- 

 tion is being made. Any sharp edges of the molars must be removed 

 by the tooth-rasp. Any supernumerary tooth which interferes with 

 mastication or any tooth which is fractured or loose should be extracted. 

 In performing such operations it is desirable to throw or cast the ox, 

 and to have its head held securely, so as to enable the operator to do 

 what is necessary without difficulty. 



CARIES OF THE TEETH. 



The presence of caries may be suspected if the mouth exhales a bad 

 odor, and if the animal occasionally stops during mastication as if it 

 were in pain. The existence of caries in a molar tooth may be ascer- 

 tained by examining the mouth in the manner already described. If 

 one of the molars is found to be carious it should be extracted, if the 

 caries is so extensive as to render other means of treatment impracti- 

 cable. When the crown of the tooth has been destroyed and only the 

 stump or root is left, extraction will be impracticable. In such cases it 

 is best to sell the animal to the butcher. 



ACTINOMYCOSIS OF THE JAWBONES BIG-JAW LUMP-JAW. 

 [Plates xxxix, XLI.] 



The disease which we have now to consider is generally known among 

 farmers and cattle dealers under the two latter designations. Atten- 

 tion is first directed to the animal by a swelling or enlargement of the 

 jawbone, and the opinion generally expressed when such a swelling is 

 observed is that the animal has received some severe contusion which 

 has been the starting point of the swelling. It is found, however, that 

 when a blow or contusion is the starting point of such a swelling it 

 rarely if ever ulcerates, and that the continuous application of cold 

 water checks the growth of a swelling which is merely the result of 

 mechanical injury. In the disease we arc now considering, however, 

 the application of cold water does not exercise the least influence in 

 checking its progress. The swelling described may affect either the 

 upper or lower jaw, or it may affect both at the same time, and pro- 

 duce considerable swelling of the soft tissues as well as enlargement of 

 the bony structure. As a result of the swelling described the molar 

 teeth of the upper and lower jaws may be pushed out of their natural 

 position so that they are no longer in apposition, and they consequently 

 can not serve the purpose of masticating the food. It may also happen 

 that from degeneration of the tooth-sockets the teeth drop out. This 

 result may be suspected when the animal becomes unable to masticate 

 its food. As a result of ulceration it frequently happens that an open- 



