BIOLOGICAL PRODUCTS (VETERINARY). 
675 
being' increased as treatment is continued. Injections should be 
repeated at intervals of from three to seven days, as indicated by 
the symptoms. If there is an aggravation of symptoms either 
local or constitutional following an injection, further treatment 
should be withheld until they have subsided. 
The results obtained by the use of bacterial vaccines, properly 
prepared and administered, are indeed gratifying. • Many stub¬ 
born suppurative conditions, such as fistulous withers, poll evil 
and quittor, which do not yield to ordinary surgical and medicinal 
treatment, are benefited and completely cured by bacterial vac¬ 
cines. Febrile disorders due to bacterial infections, in many cases 
respond to bacterial therapy and make rapid recoveries. 
Antisera. 
Tetanus Antitoxin. As mentioned before, an antitoxin is a 
reactive substance developed in the blood of an animal injected 
with toxin. Tetanus antitoxin is one of the best known of the 
standard antitoxins. It consists of the serum of a horse which 
has acquired a high degree of immunity to tetanus by repeated 
injections of the specific toxin. 
In tetanus the specific organism remains localized at the point 
of infection. Multiplication of the organisms take place at this 
point, with the production of their powerful toxin. The toxin 
has special affinity for nerve tissue, and is supposed to be ab¬ 
sorbed by the nerve endings with which it comes in contact and 
conveyed by the nerves to the central nervous system. The ex¬ 
pected action of any antitoxin is to neutralize or render harmless 
its specific toxin. In the case of tetanus antitoxin this result can 
only be accomplished before the toxin is fixed in the nerve tissues. 
Therefore, the administration of tetanus antitoxin should begin 
as soon as possible in order to accomplish the best results. 
As a prophylactic agent against the disease this product is 
now generally recognized as a specific. It is especially indicated 
in the treatment of animals affected with wounds, such as nail 
pricks and punctures, the nature of which are conducive to the 
development'of the tetanus organisms. Many operators will not 
undertake an operation of any consequence without first admin- 
