912 EXPERIMENT STATION RECORD. 



ment in connection with suitable treatment for abortion will practically control 

 the problem of sterility in milch cows. 



Contagious abortion among cattle, A. II. Cory (Queensland Agr. Jour., 16 

 (1905). No. 3, pp. 2)9. 250). — A brief account is given of the cause, symptoms, 

 treatment, and prevention of this disease. The antiseptic solutions recom- 

 mended in the treatment of the disease are carbolic acid 1 : 100 parts of water 

 or corrosive sublimate 1 : 2,000 parts. 



Cowpox, Desmond (Jour. Dept. Agr. So. Aust., 9 (1905), Ao. 5, pp. 328-334, 

 /7 -, /x < f |. — This disease occurred in an extensive outbreak in a dairy which was 

 later examined by the author. Seven cows were found to be affected in the 

 herd. The usual antiseptic precautions are recommended in the control of the 

 disease. 



Eradication of African coast fever, C. E. Gray (Transvaal Agr. Jour., 3 

 (1905), Ao. 12, pp. 696-699). — Additional experiments on the life history of the 

 brown tick, which is the main factor in the dissemination of African coast 

 fever, indicate that it may be possible to stamp out the disease by the observ- 

 ance of certain precautions. If susceptible animals are kept away from 

 infested tields for a period of 12 months they may then be allowed to graze on 

 such ground. The explanation of this fact is that the ticks have died in the 

 meantime. Tick starvation in connection with thorough dipping of infested 

 eattle may lead to the eradication of the disease. 



Further experiments to note how long an area remains infected with east 

 coast fever, A. Theiler (Transvaal Agr. Jour., 3 (1905), Ao. 12, pp. 700-706). — 

 On sheep allowed to graze with cattle infested with the brown tick, this tick 

 was not found to occur in great numbers. The most prominent species on 

 sheep were Hyalomma cegyptium, Amblyomma hebrceum, Bhipicephalus simus, 

 and R. evertsi. 



Experiments were carried out by the author to determine the possibility of 

 eradicating the disease from infected fields. It was found that as soon as the 

 ticks were dead from starvation the area was no longer dangerous. Care must 

 be exercised, however, to prevent other animals from carrying the ticks from 

 place to place. In one instance, a brown tick was found on a wild hare. 



It is recommended that as soon as the fever temperature appears in animals 

 affected with African coast fever they be confined in inclosures so that ticks 

 from them will be unable to get upon the pastures. The incubation period of 

 coast fever is not more than 20 days. During this time ticks on cattle do not 

 become virulent. It should also be remembered that the ticks do not acquire 

 the blood parasite even after the first few days of the disease, and after the tick 

 falls to the ground it must first undergo a moulting process before it is able to 

 infest healthy cattle. This period lasts for not more than 20 days. 



In experiments with virulent brown ticks the author was able to reproduce 

 the disease in 8 out of 9 cases. It was also found that two ticks were sufficient 

 t<» cause a development of fever. 



Redwater in cattle and its treatment with Damholid, Westermann (Berlin. 

 Tlerdrztl. Wchnschr., 1905, Ao. 52, pp. 881, 882). — In the early experiments 

 carried out by the author in treating redwater with injections of Damholid, the 

 animals all died of what appeared to be malignant edema. Later experiments, 

 however, showed that if the inoculation was made during the early stages of 

 the disease it always has a decidedly beneficial effect. 



Good results are also obtained from the administration of 50 gm. of Damholid 

 daily through the mouth. In most cases the treated cattle recovered entirely 

 within 3 days. Damholid was also used in one case of advanced tuberculosis, 

 being fed in water at the rate of 50 gm. per day. At the beginning of the treat- 



