HORSE SICKNESS. 485 



PREVENTIVE MEASURES.— We have seen from the foregoing 

 remarks on this disease, that if horses be at grass during a sickly 

 period, they should be sent to some dry and unaffected grazing 

 ground beyond the limits of the disease, or should be kept in a 

 kraal at night, and not allowed to graze until the sun has removed 

 all the dew from the grass. Stabled horses should be fed on dry 

 food, such as oaten hay, and Indian corn or oats, and should on 

 no account be given any grass which has not been thoroughly 

 dried, 



ACQUIRED IMMUNITY.— Dr. Edington has performed admir- 

 able work in obtaining a serum which, by inoculation, confers im- 

 munity from horse sickness. The practical application of this 

 protective agent is a question which has not yet been settled. 



It is a common belief in South Africa that horses which have 

 recovered from an attack of horse sickness possess a life-long 

 immunity from it, and that consequently their value becomes much 

 enhanced in frequently infected districts. While in South Africa 

 I was unable to obtain any exact information on the subject of these 

 " salted " animals, which I had imagined were an ordinary article 

 of commerce in that country. In fact, I failed to find a single 

 animal of the kind, although I made many enquiries, everywhere I 

 went. The few persons who had, so they said, seen " salted " horses, 

 informed me that these animals present a dejected and debilitated 

 appearance ; that the skin about their head and neck is unusually 

 loose and wrinkled; and that they are liable to relapses of the 

 disease, though in a milder form. Mr. Wiltshire, late Colonial 

 Veterinary Surgeon of Natal, told me that " salted " horses invari- 

 ably die from horse-sickness, if they be allowed to live long enough. 

 I see from a photograph of a supposed " salted '^ horse, that the hair 

 of his mane and forelock stick out in a particularly rough and dis- 

 ordered manner, so that it would be impossible to have made the 

 mane lie on one side or the forelock to fall straight down. I have 

 always heard that " salted " horses have this peculiarity of 

 the mane, forelock, and tail. As far as I can learn, the 

 only peculiarity of serum-salted horses is that they " are 

 subject at much later and irregular periods to attacks of 

 fever. Such attacks have no relation to fresh infection, 

 as I have found them to occur in all salted horses which 

 I have kept under close observation in the stable. The 

 attacks vary greatly both in degree and duration ; they may 

 last for one day, or may extend over as many as six days " 

 (Edington). I am inclined to think that the " salted " horses of 

 popular South African repute are those which are suffering from 

 the disease communicated by the tsetse fly (p. 459), 



