12 
Farmers' Bulletin 11^6. 
disease has existed only in restricted areas and where sanitary- 
considerations demand its prompt extirpation. 
Tho Bureau of Animal Industry nevertheless has conducted ex- 
periments alon<^ lines of treatment in animals affected with the 
disease. Various drugs likely to be most useful in combating try- 
panosome "infection were used, but the results were unsatisfactory. 
The very high cost of these drugs, together with the expense of 
handling the animals, would make such treatment impracticable even 
though beneficial results had been obtained. 
METHOD OF ERADICATION. 
Sanitary measures looking to the eradication of dourine must de- 
pend on the principle that horses infected with the disease should 
be prevented from breeding. This conclusion is well founded, for in 
spite of the possibility of recovery there are, as a matter of fact, 
frequent relapses, and trypanosomes may exist for many months in 
the sexual organs of animals apparently recovered. Therefore it is 
very essential to destroy diseased animals as soon as possible. The 
objections to spaying the mares and castrating the stallions is that 
such mares on the open range may be covered by stallions and that 
infected stallions even after castration may cover healthy mares. 
Dourine, being conve3^ed under natural conditions solely by the act 
of coition, is not a difficult disease to stamp out in a farming com- 
munit}', but eradication is a more difficult task on the open range. 
With good cooperation among Federal Government officials. State 
authorities, and horse owners, however, these difficulties can be over-" 
come. 
A number of the veterinarians of the Bureau of Animal Industry 
are stationed in States where dourine exists, and they cooperate with 
the State veterinarians and their deputies in the work of eradication. 
In the spring of the ^^ear, before the animals are bred, samples of 
blood serum are drawn from all breeding animals in districts where 
dourine exists or is suspected. These samples of serum are properly 
identified and forwarded to the Pathological Division of the bureau 
and are subjected to the complement-fixation test for dourine. The 
animals are held in virtual quarantine until the results of the test are 
received. Animals whose serums give positive results are destroyed. 
The owner is reimbursed for the loss of the animal, the State and 
Federal Governments sharing the expense equally, but not to exceed 
$100 on the part of the latter. On the Indian reservations the entire 
expense is borne by the Federal Government. Animals whose 
serums give negative results are considered to be free of infection 
and are released for breeding. 
About 50,000 samples of serum are tested annually. The percent- 
age of reactors is growing smaller each year, and the outlook for the 
complete eradication of dourine in the near future is bright. 
o 
