INFECTIOUS DISEASES OE CATTLE. 



397 



inoculation of test rabbits with the brain or cord of a rabid animal 

 will produce the disease with characteristic symptoms after an inter- 

 val of fifteen to twenty days. This period of incubation is much longer 

 than in tetanus, since the inoculation of rabbits with tetanus cultures 

 invariably results in death after a short period and usually within 

 three days. The positive evidence that a rabid dog has been near 

 cattle would greatly assist in making a decision in doubtful cases. 

 The disease in dogs is pretty well recognized by most people, but in 

 case a suspected dog is killed it is desirable to open the animal and 

 examine the contents of the stomach. While food is absent, a variety 

 of odd things may be present which the abnormally changed appetite 

 of the rabid dog has induced it to swallow. Among such things may 

 be straws, sticks, glass, rags, earth, pieces of leather, and whatever 

 the animal may have encountered small enough to be swallowed. 

 This miscellaneous collection in the stomach of dogs, together with 

 absence of food, is regarded by authorities as a very valuable sign, 

 and may be made use of by laymen in case of doubt. In important 

 cases, however, the head of the dog, cow, or other suspected animal 

 should be removed and sent to the nearest biological laboratory, where 

 a positive diagnosis can be made within thirty-six hours by the histo- 

 logical examination of the plexiform nerve ganglia, and within two 

 or three weeks by the intracerebral inoculation of rabbits with an 

 emulsion of the brain of the suspected animal. 



Treatment. — This is useless after the first appearance of symptoms. 

 When, however, a wound inflicted by a rabid animal can be discov- 

 ered, it should be immediately cauterized or even completely extir- 

 pated, care being taken to cut entirely around the wound in the * 

 healthy tissues. For cauterizing the wound, fuming nitric acid, the 

 hot iron, and 10 per cent solution of zinc chloride are the most effica- 

 cious. To afford an absolute protection, this should be done within a 

 few moments after the bite has been inflicted, although even as late 

 as a few hours it has been known to thwart the development of the 

 disease. 



Pasteur has originated and perfected a system of preventive inocu- 

 lation against this disease which has greatly reduced the mortality in 

 human subjects. Its application to animals, however, is more diffi- 

 cult, requiring considerable time and expense, and is therefore only 

 economically applicable in cases where very valuable animals are bit- 

 ten by dogs known to be mad. Sanitary regulations which seek to 

 control effectively the disease by exterminating it among dogs are most 

 likely to prove successful. The measures which are adopted to this 

 end can not be discussed in this place, but it is a striking fact that 

 where the muzzling of all dogs has been rigidly enforced, as in Eng- 

 land and in certain German districts, the disease has been practically 

 stamped out. 



