86 
Parasites of Cattle and Sheep. 
may sometimes be advisable to adopt this plan, but the general 
outcome of the inquiry of the last Departmental Committee 
indicates that certain dips are effectual and easy of application, 
while it is important that every sheep shall be subjected to some 
effectual process. The essence of the prevention of scab of 
course lies in the cure, i.e., destruction of the scab mite. 
That dipping is effectual for the destruction of the scab 
mites and the skin parasites, which usually co-exist on sheep, 
and cause much irritation, restlessness, loss of flesh, damage to 
the fleece, and aid the extension of scab, has for a long time 
been recognised, and the practice has been adopted by flock 
masters who realised their responsibility and the advantages 
to be gained. The momentous decrease of the disease since 
the compulsory dipping Order came into force, gives good 
grounds for hoping that this pest may be exterminated within 
a reasonable time. This will, however, depend on the manner 
in which the provisions of the Order are carried out. The first 
essential is that the dip be effective ; ’ the second, that the 
dipping be properly performed. 
Two other species of scabies, mange, or scab parasites may 
be mentioned, although they are not commonly recognised as 
inducing diseases in sheep in Great Britain. 
. Sarcoptic Mange. — One species, Sarcoptes, usually confines 
its attacks to the parts covered with hair, i.e., head and legs. 
It is the burrowing mite and its description in reference to 
cattle will suffice. It is rarely met with in Great Britain. 
Symbiotic Mange. — Another species, the Symbiotes or 
Chorioptes, have oval bodies and thick legs, and move about 
in groups, but are rarely found elsewhere than on the legs. 
Here they induce irritation, in some cases swelling and the 
formation of sores, giving rise to a condition of the legs, 
especially above the claws, included under the head of “ dew 
rot” ; while some writers, without much show of proof, regard 
this parasite as the cause of one form of foot rot. 
Both these forms of scabies yield to cleanliness and the 
application of sheep dips and other medicaments fatal to the. 
“ scab ” parasite. 
Ticks . 1 — The parasites of the family were referred to at 
length under “ Ticks'” in cattle, and will only require brief 
notice here. The error of calling the common “Ked,” or 
Melophagus ovinus, the sheep tick has led to the view that 
ticks are very commonly found on sheep in almost every part 
of the kingdom. This is probably incorrect. The idea of such 
a wide and general distribution is not based on any reliable 
reports yet available. They are, however, common in some 
dis tricts, notab ly hill pastures in the Border counties, the 
1 See also page 274 of this Volume. 
