ANIMAL PARASITIC SKIN DISEASES. 779 



Dermatopliytic, tliose which are dependent on vegetable 

 existences. 



A. DERMATOZOIC, ECTOZOIC;, OR ANIMAL PARASITIC SKIN 

 DISEASES. 



Of diseases of this group to which the skin of the horse is 

 subject, the chief are, Scabies or Mange, Phthiriasis or lousi- 

 ness, and the disturbances consequent on the presence in the 

 dermal tissues during certain periods of their life-cycle of 

 such parasites as the Filaria medinenses and Filaria multi- 

 papillosa, etc. 



Although during a short period of our summer months, and 

 under particular conditions, certain dipterous insects cause our 

 horses considerable annoyance, both when at work and when 

 grazing in the fields, Ave have in Great Britain really no serious 

 or very troublesome affections attributable to attacks of winged 

 insects. 



The Filaria medinenses or Guinea-worm, so common and 

 troublesome as attacking or chiefly manifesting itself in con- 

 nection with the skin of man in certain parts of the world, has 

 been observed, in those situations where abounding, to locate 

 itself in the subdermal tissues of the horse, and of course in- 

 ducing there a certain amount of local and circumscribed 

 irritation. 



Filaria multipapillosa. — This nematode, said to be common 

 enough as an irritating visitant of the skin of the horse over 

 considerable parts of Central Europe, is to us chiefly interest- 

 ing from the circumstance that horses bred there when brought 

 to this country are said in man}^ instances to exhibit, for a 

 lengthened period after their arrival here, symptoms indicative 

 of its presence in the cutaneous tissues. Those which may be 

 regarded as diagnostic are the appearance suddenly and at 

 irregular intervals, chiefly over the neck, the superior scapular 

 region and back, of very minute discharges of red blood, as if 

 the skin had been punctured with a needle. 



The few in which I have encountered this cutaneous h;emor- 

 rhage were Hungarian horses, and they had not been more than 

 twelve months in this country. Knowing that such symptoms 

 had, byContmental observers, been connected with the existence 

 in the skin-tissues of a particular parasite, I was inclined to 



