530 



GENERAL THERAPEUTIC MEASURES 



ripally because their size enables the drawing of large volumes of blood. 

 If the horse is to be treated for the production of antitoxin small amounts 

 of the respective toxin are at first injected. If the animal is to be treated 

 with antibacterial serum, suspensions of the bacteria of the specific dis- 

 ease are injected. Periodical potency tests are made consisting in agglu- 

 tination, complement fixation test and the ability of the serum to protect 

 other animals. When a suitable potency test is obtained a quantity of 

 blood is drawn from the jugular vein into sterile containers. After 

 standing 2i hours the separate serum is siphoned off, properly preserved, 

 if necessary Berkefeld filtered and filled into final containers. 



Immune sera contain either antibodies which have an immediate 

 neutralizing action upon the toxins generated during the course of the 

 disease; or antibodies which have the power of helping to destroy or 

 render inert the living organisms themselves. Hence the term "anti- 

 toxic sera" for those sera possessing antibodies which neutralize the 

 toxin; and the term "antibacterial sera" for those which contain anti- 

 bodies capable of helping to destroy or render inert the organisms causing 



the disease. Immune 

 sera are assimilated 

 most rapidly if ad- 

 ministered intraven- 

 ously. This applies 

 especially where it is 

 desired to administer 

 for therapeutic ac- 

 tion. For prophylac- 

 tic purposes the 

 inj ection is made 

 either intramuscular- 

 ly or subcutaneously. 

 In addition to 

 the foregoing there 

 are other products 

 such as sensitized 

 vaccines, sensitized 

 bacterins, germ free 

 extracts, natural and 

 artificial aggressins and bacterial filtrates, employed for the protection of 

 animals against disease; but with all these products the principle of their 

 action is the same and consists of the production of protective substances 

 against their respective infections. 



Taking up the uses to which biological products are put, they may 

 be divided into four groups: 



1 . Those that are used as prophylactic agents only, such as anthrax, 

 rabies, and blackleg vaccine. 



2. Those that are used principally as curative agents, such as vari- 

 ous immune sera. 



3. Those used for both prophylactic and curative purposes, such as 

 various bacterial vaccines, anti-anthrax serum, tetanus antitoxin. 



1'. Those used as diagnostic agents, such as mallein and tuberculin. 

 In the preventionDf^/fAZefflbdy M/fe(caSQ#<Saiseases in both man and 



Bleeding an Hyperimmunized Horse to Produce 

 Serum 



