8 
COLORADO EXPERIMENT STATION 
under which they are most dangerous, would of itself be a great help to 
the stockman. 
Blackleg. 
By Dr. C. L. Barnes. 
Blackleg (Symptomatic Anthrax) is a disease of young cattle and 
is caused by a germ. Most diseases of livestock are attributable either 
directly or indirectly to bad care and management, but this disease in¬ 
variably strikes down the calves that have received the best care and 
are in the best condition. 
Symptoms: One of the first symptoms noticed is the sick animal 
remaining away from the herd, usually lying down and not chewing its 
cud. If the animal is forced to move it appears stiff, usually in one 
fore leg. If this leg and shoulder be examined closely, it will be found 
that the muscles are swollen and tense. This swelling gradually in¬ 
creases as do all of the symptoms. The peculiar crackling sound, 
emitted when the hand is rubbed over the tumor is caused from gas 
which has accumulated under the skin. 
If the swelling be lanced, a dark, frothy, bloody fluid runs out 
which swarms with blackleg germs. Death usually occurs in from six 
to forty-eight hours after the first symptoms are noticed. 
The Season of Greatest Loss: Blackleg occurs in all seasons of the 
year. Reports from 1,656 stockmen show that May and June, and 
September and October are the months when the greatest losses occur. 
It would seem that it is greatest in wet seasons, for the sole reason 
no doubt, that feed is better in the wet season, and this is conducive to 
thrift and increases the susceptibility to the disease. 
Treatment: As to treatment there is none. Practically all ani¬ 
mals contracting the disease die. Our only hope is in the prevention. 
Prevention: The fact that young cattle in a thriving condition 
are more susceptible, has led to the general belief that anything that 
will deplete the condition will act as a preventive, accordingly, various 
means of depletion have been tried such as chasing the animals, reduc¬ 
ing the feed and water, bleeding, physic, seton through the dewlap, etc. 
This sort of thing however is very discouraging to the man who has 
been striving to keep his cattle growing, and besides when the disease 
has once appeared in the herd, such measures will not check it. 
Vaccination: Vaccination will positively prevent blackleg; this 
is proven in laboratories where animals that have been vaccinated re¬ 
fuse to take the disease by inoculating them with the virus of diseased 
animals. The reason that some have not had satisfactory results from 
its use is that either the vaccine is not good or has not been properly 
given. Again occasionally a man will wait until , his calves begin to 
die before vaccinating, and if they continue to die, he blames the 
vaccine. In such cases the calves were infected before vaccination and 
his efforts were and always will be in vain. Those who have made a 
regular practice of vaccinating every spring and fall and have exercised 
care in the work have generally reported excellent results. 
