e after they have been under
treatment for some time, the dipping should not be discontinued until a
number of careful inspections show that the cattle are free of ticks. If
ticks continue on cattle until cold weather and then finally disappear it
should be borne in mind that in all probability eradication has not been
accomplished and that there may be engorged females, unhatched eggs, and
inactive seed ticks on the farm or range, and that even if the cattle
should remain free of ticks during the winter they may become reinfested
the following spring. In any case in which ticks disappear from the cattle
and treatment is discontinued, the cattle should be watched very carefully
for ticks until ample time has elapsed to leave no doubt that eradication
has been accomplished.

As a general rule it has been found that if dipping is begun in March and
systematically and thoroughly done, all cattle being dipped every 14 days
until November, complete eradication will be secured. In dipping, each
animal should be completely covered by the dip. To prevent any animals from
going through the vat without becoming wet all over, a man, provided with a
forked stick, should be stationed at the middle of the vat to shove under
those that have not been completely submerged.

Dipping is the only really satisfactory method of treating animals for
ticks. In cases of emergency, however, or where there are not cattle enough
within a radius of several miles to warrant the construction of a vat in
which all the cattle of the community may be dipped, spraying may be
advisable. In spraying animals the work should be done with great
thoroughness and every portion of the body treated. An animal can not be
sprayed properly unless it is tied or otherwise held, nor can good results
be obtained unless the hair and skin are thoroughly wetted.

_Preparation and use of arsenical dips._[8]--After experimenting for many
years to discover a practical method for dipping cattle to destroy ticks
without injury to the cattle, the Bureau of Animal Industry has developed a
very satisfactory arsenical dip. Two formulas are given for homemade dips,
one known as the "S-B" (self-boiled) and the other as the boiled dip. The
former is the one usually employed.

_The S-B dip._--The formula calls for two stock solutions, arsenic stock
and tar stock, which must not be mixed except in the diluted dipping bath.

Arsenic stock requires the following materials ready to hand