The Birmingham age-herald., 1909-07-03
ACTIVE FIGHT ON
 THE CATTLE TICK Agricultural Department Is Doing Good Work STUDY OF THE DISEASE Many Cattle Appear Healthy, But They May Have the Fever In the
 Blood and Transmit
 Disease.
STUDY OF THE DISEASE

Washington, July 2.-(Special. )-The mf- croscopic parasite which causes the dis ease known as Texas fever or tick fever of cattle is found In the blood of af- fected animals and is transferred from one to another by means of the fever tick. A remarkable feature of this transaction is that the disease producing parasites are transmitted through the eggs of the tick that draws the blood, and not directly by the old tick, as engorged tick after dropping from the host (cow) dies without ever attaching itself to another animal. But its offspring. produced by the eggs laid after it drops off and before it dies, carries the infection and inoculate the first COW they get on.
 The length of time elapsing between the exposure of susceptible cattle to infec- ton by ticks and the appearance of Texas fever among them is dependent upon the climate and the development of the ticks. Thus, if northern cattle are placed on pastures, highways or In pens. cars, etc., in summer immediately after the prem ises have been infested with ticks from southern cattle, Texas fever may occur in from 30 to 60 days, as the female ticks which drop from southern cattle must lay eggs, and these must hatch before the northern animal becomes infested with ticks and thereby inoculated with the dis ease. After the seed ticks become at tached to the animal the disease will ap- pear in about 10 days in summer or a somewhat longer period in winter. In fact, the disease may occur before the ticks are large enough to be seen without a very careful search
 One objection that has been advanced against the fact that the cattle tick is a carrier of Texas fever Is that cattle are sometimes found to be suffering with the disease without showing the presence of ticks on their bodies. This condition in the case of southern cattle may be ex- plained by the fact that the animal all ready had its blood inrected with the parasites and under normal conditions was resistant to Texas fever; however, as result of lowered vitality caused by some other disease, or by exposure, privation, injury. rough handling, etc., this resistance has been reduced and finally overcome, and the parasites at last succeed in producing the disease. oii lic olfcI udlius when InlS disease Is observed in northern animals, the young seed ticks may be so small and so few in number as to be unopserved
 Under certain conditions, as when liv- ing on horses, mules, etc., the ticks lose their 1nfectiousness, and when southern cattle not previously infested with any but these noninfectious ticks come in con tact with infectious ticks they are just as susceptible as cattle raised on tick-free pastures.
 Many cattle appear perfectly healthy and yet are infected with ticks and have the fever parasite in their blood Some times the owners can not understand why animals should be regarded as dan gerous to others. and consider 1t unjust that they should be subjected to quaran- tine restrictions. The fact is that such cattle have usually contracted the dis ease in a very mild form at an early age and have become immune to further attacks. although sttll carrying the para site in their blood. They are dangerous because the fever parasite in their blood may be transmitted at any time to sus- ceptible cattle by ticks.
 While the disease may be produced ar tificially by bysinoculating a susceptible an- imal with the blood of an infected one, it is spread naturally only by the ticks By exterminating the ticks therefore, the disease can be stamped out and the quar- antinescan then be removed
 The discovery of the part played by the tick in the spread of Texas fever was made by the Bureau of Animal In- dustry of the United States Department of agriculture in 1891, and the same prin- ciple has since been found to apply to the transmission of malaria and yellow fever from man to man by mosquitoes, and to the spread of certain other dis eases.
 Publications containing full information about the ticks and giving directions for getting rid of them may be obtained free on application to the Bureau of Animal Industry. Department of Agriculture, Washington.