SOME SKIN AFFECTIONS 199 



this fact must be borne in mind when dealing with the 

 trouble. 



Recurrent attacks of mange are probably due to 

 inefficient treatment of the ova of the parasites. Although 

 microscopic examination is necessary for the verification 

 of the several distinctive forms of mange, the disease 

 presents certain clinical features which do to a certain 

 extent enable one to form a fairly reliable opinion as to 

 the particular variety of mange from which the animal is 

 suffering. 



Sarcoptic mange usually makes its appearance in the 

 region of the withers, the face, the neck and the shoulders, 

 in fact whenever mange appears in front of the wethers, 

 excepting beneath the mane and between the ears, one 

 may accept its appearance in the situations referred to 

 as good or fairly good positive evidence that the disease 

 is sarcoptic mange. On the other hand the appearance 

 of mange on other parts of the body favours the opinion 

 that the trouble is of the psoroptic variety. The most 

 practical test for the existence of mange is to scratch the skin 

 on the withers, neck, etc. 



Mange is spread by direct or indirect contact ; thus, for 

 instance, it may be carried by an infected horse coming 

 directly into contact with another, or through the 

 medium of stall posts and stable fittings, through groom- 

 ing appliances, the last-named being one of the commonest 

 channels of infection. The hands and clothing of atten- 

 dants may easily transmit the disease if these are infected. 

 The bedding may perpetuate the disease, consequently it 

 is very necessary that this should, after removal from the 

 stable, be burned. The harness and the shafts of carts 

 may afford a chance of re-infection. 



When mange appeals amongst a stud of horses in addition 

 to immediate notification all the affected animals must be 

 isolated, and the in-contacts kept under observation for at 

 least three weeks. Diagnosis is based upon finding the 

 parasites, a search for which is made by taking one or 



