THE PROBLEM OF HORSE SICKNESS. 79 



breeding-places, etc. We assume it is a mosquito or an insect 

 with similar haljits. The destruction of all mosquito-life would, 

 in all i)rol)a1)ility. remove the disease. This is an undertaking 

 which might be carried out in definite localities, and should be 

 encoiu^aged. It would, however, be an undertaking of enor- 

 mous magnitude if undertaken over a large area. That is can 

 be done has been shown by the anti-malaria and anti-yellow 

 fever campaigns in the various parts of the world, the striking- 

 example of some magnitude being the sanitation of the Panama 

 Canal zone. 



Tbcre remains, therefore, at present the alternative, via.. 

 the protection of the individual er|uines. The susceptible equines 

 must be considered from two points of view, z'ia., whether thev 

 can be stabled during the dangerous season, or whether they 

 have to be kept in the open. Stabled animals can be protected 

 against the disease effectively, provided the stable is insect proof. 

 The efficacy of this method cannot be doubted; where it failed, 

 the cause of failure can be found. Unfortunately stabling is not 

 always applicable ; horses and mules must be used at any time, 

 and frequently during the night. Under such conditions a 

 protection applied to the skin comes into consideration. For 

 the past 15 years the Veterinary Division has advocated this 

 method, and has recommended the use of paraffin, or a mixture 

 of paraffin and oil, su])pliefl as a simple and convenient remedv. 

 The use of paraffin and oil suggesterl itself from the observation 

 made during the war. Horses hadlv suft'ering from mange were 

 treated with a mixture of paraffin, linseed oil, and sulphur, and 

 were allowed to run during the horse-sickness season. It was 

 a striking fact that horses so treated did not contract horse- 

 sickness. Paraffin has since for many years been made use of 

 by Transvaal farmers. The method is not infallible, and could 

 be inij^roved. Antiseptics of the tar-derivation group have been 

 tried as well, and are used by many, and in particular as a 

 spray. Avith diff'erent results. Where a great number of horses 

 are concerned, the ap]:)licatinn of similarly acting remedies in a 

 convenient and economic manner becomes necessary. Since the 

 introduction of the dipping tank, the tank suggested itself for this 

 purpose. Our first exneriment. undertaken in 1912 in Natal, 

 with the usual arsenical dii)]Mng fluid, was, however, not en- 

 couraging. Of six horses which were regularly dipped at 

 weekly intervals, four contracted horse-sickness and died. There 

 was a doubt about the diagnosis of the disease, but it was sup- 

 Dorted by subsequent tests. In the pamphlet oublished in 1912, 

 dealing with the result of diopinp- cattle in Natal, reference is 

 made to the results obtained with dipping horses exposed to 

 horse-sickness. They were indifferent, and not conclusive. Very 

 enc'^uaging results were obtained by the De Beers Company, who, 

 during the last year, dipjDed their horses and mules at regular 

 intervals in a cattle dip to which was added three gallons of 

 lin-eed oil and two gallons of paraffin oil for every 300 horses 



