RABIES 315 



The quickest way to determine with certainty the nature 

 of ih" 1 rouble is to confine the dog and note the symptoms. 

 The disease is invariably fatal, and death is commonly pre- 

 ceded by a definite sequence of symptoms, so that there can 

 le no mistake in the diagnosis. The diagnosis should be 

 made as quickly as possible, for if preventive treatment is 

 to be applied, it must be administered without delay, since 

 it is of no avail if not begun until the symptoms appear. 

 If it is impossible to secur.e and confine the dog alive, the 

 diagnosis can be made by a microscopic examination of the 

 brain. The head should be removed, packed in ice and 

 sawdust, and sent to the laboratory that is maintained by 

 most Stales and large cities for such work. In killing the 

 loir, care should be taken not to injure the brain or spinal 

 cord. 



Preventive treatment. The treatment used to prevent 

 the development of the disease in persons bitten by a rabid 

 animal was one of the triumphs of Pasteur. The organism 

 found in ordinary cases of rabies can be increased in viru- 

 lence for rabbits by passing it through a series of animals. 

 The so-called fixed virus will kill a rabbit in seven days, 

 when introduced beneath the membranes of the brain. If 

 the cord is removed from the animal immediately after 

 death and allowed to dry over caustic potash, the virus be- 

 comes attenuated, the extent of the attenuation depending 

 on the length of the drying process. The preventive treat- 

 ment consists in giving hypodermic injections of a 'suspen- 

 sion of the dried cord. The first injections contain mate- 

 rial that has been dried for about two weeks, while the sub- 

 sequent injections are made with material that has been 

 dried for a shorter period, until at last an injection of the 

 fresh cord can be given without danger. Injections are 

 made for a period of twenty-one days. Of all the persons 

 known to have been bitten by rabid animals, to which the 



