260 INSECTS AFFECTING DOMESTIC ANIMALS. 
RELATION OF TICKS TO TEXAS FEVER. 
That ticks have a relation to Texas fever was held many years ago 
by people acquainted with Southern cattle, but no valid reason for 
such belief could be adduced, and the idea was looked upon by the 
scientific world as only one of the popular notions that come from 
taking coincidences as meaning cause and effect. 
When, however, the study of the disease was entered upon from the 
standpoint of modern bacteriology, it was learned that the ticks may 
have a most important relationship as carriers of the disease germ and 
thereby serve as agents of infection. It is now generally accepted 
that even if the ticks are not an essential means of transmission, they 
are so generally the source of infection that their destruction constitutes 
a most important factor in the prevention of the disease. 
PREVENTION AND REMEDY. 
Since the ticks get access to the animals mainly by being brushed 
upon them from the leaves of bushy plants or trees, the keeping of 
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Fic. 153.— Dermacentor americanus; male—enlarged (original). 
cattle away from wooded pastures is recommended as one advantageous 
method of preventing their injuries. Weed strongly recommends the 
feeding of sulphur and salt as a preventive. 
For direct treatment there is probably nothing that equals the dip- 
ping process, by which the whole animal is completely drenched with a 
dipping solution. Dr. Francis, after using a spraying outfit for the 
purpose, says that he has discarded it entirely for the more satisfactory 
method of dipping, special preference being given to a dip of cotton- 
seed oil. Full details of this process and the form of vat required are 
_ given in the chapter on remedies and their application. 
. 
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