CHAPTER XX 

 SOME DISEASES OCCURRING ABROAD. 



TSETSE-FLY PLAGUE. NAGANA 



FLY disease or nagana occurs in many regions of Africa 

 south of the equator, and causes enormous losses 

 amongst horses in those districts where the tsetse-fly 

 abounds. These flies are a trifle larger than the house fly ; 

 have overlapping wings when resting. The mouth is specially 

 adapted for piercing and sucking, and it makes the best use 

 of this arrangement so far as itself is concerned. It eagerly 

 attacks man and certain other animals, but the horse is the 

 one that it does so much harm to. 



River banks and hot swampy places are the favourite 

 haunts of the tsetse-fly, and those who now travel through 

 those parts usually swathe their horses in clothing so as to 

 prevent the flies from fixing on to the animal. 



Nagana is due to a low form of animal (protozoan) parasite 

 circulating in the blood, and transferred from horse to horse 

 through the medium of the blood sucking tsetse-fly previously 

 alluded to. Nagana is a Zulu term, meaning depressed in 

 spirits. When a horse is attacked with this fatal disease, the 

 coat begins to stand up, and swellings appear under the belly, 



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