474 FARM ANIMALS 
germs grow and produce a poisonous toxin that is said to be the 
most pewerful produced by any bacteria. This toxin acts on the 
nerve centers of the brain and spinal cord, causing extensive spas- 
modic contraction of the body muscles. It may be largely prevented 
by the careful disinfection of wounds, and the use of anti-tetanic 
serum. In most localities the proper treatment of the wound is a 
sufficient preventive measure, but in localities where the disease is 
common the anti-tetanic serum should be used as soon after the 
injury has occurred as possible. Many boys and girls lose their 
lives from this disease through firecrackers after a Fourth of July 
celebration. 
13. Texas fever.—Caused by an organism which lives 
within and breaks up the red corpuscles of the blood. It 
is transmitted by the cattle tick. The eggs laid on the 
ground by the female 
tick after falling off the 
cattle hatch, and the 
little creatures attach 
themselves, by prefer- 
ence, to the tender skin 
on the escutcheon, the 
inside of the thighs, and 
on the base of the udder. 
When very numerous 
ACUTE CASE OF TEXAS FEVER they may be found on 
various parts of the body. They remain clinging to the 
cattle until mature, and then fall off and lay their eggs 
and hatch more new ticks. 
The spread of Texas fever can be prevented in.two ways: By 
sanitary arrangements and by vaccination. Where the cattle are in- 
fested with the tick, the ticks can be killed by smearing the animals 
with a solution capable of killing the ticks without harming the 
cattle. In large herds a vat of crude petroleum is used for immers- 
ing the cattle. Vaccination is for the purpose of immunizing cattle 
that are brought from a non-infected district to an infected district. 
Calves are more immune than adult cattle. Immunity is caused by 
introducing the germ into the blood in a weakened form. This may 
be done in two ways—hby placing virulent young ticks on the calves 
or by artificial vaccination. 
14. Tuberculosis.—A disease resulting from the growth 
