196 SHEEP DISEASES: 



pick it up in the process of grazing ; ultimately it finds its way 

 into the liver. 



Sheep are more susceptible to rot than are other animals, 

 simply because they bite closer — a hog-mouthed sheep escapes ; 

 but cattle, and very many of them too, and occasionally in wet 

 seasons colts also, suffer from the ravages of the fluke. 



Rot is never seen on dry lands nor on salt marshes, and even 

 rotting grounds are safe after a frost. 



The lessons to be learned in reference to rot are — 1st, that it 

 cannot occur on dry lands, because there are no snails there — 

 hence the value of draining ; 2nd, that salt is a preventative, 

 because it kills snails as also the embryos of the worm ; 3rd, 

 that rotten sheep should be at once slaughtered, their excre- 

 ments mixed with lime or salt and the liver and intestines 

 carefully destroyed. Its existence can be detected early by the 

 victims thriving very rapidly and by the membrane of the eye 

 contracting a yellow tinge (jaundice). 



Sturdy is due to the presence of a bladder worm in the brain 

 and is so called because the animal is stupid, a synonymous 

 term in Norfolk being dunt ; and if the victim turns round to 

 one side it is known as turn-sick, gid, &c.; while, owing to 

 peculiarities of gait, affected sheep are often spoken of as " sailors," 

 " trotters " and " swervers." 



The bladder worm, or hydatid, is the immature form of one of 

 the tape-worms of the dog (the Tcvnia coenurus) ; it is known 

 as the many -headed hydatid {Coenurus cerebralis) and sheep 

 become the victims of it by taking into their stomachs, in the 

 ordinary act of grazing, the eggs (containing embryos) of the 

 tape-worm. 



The embryo ultimately finds its way to the brain either by 

 the circulation or by boring, and sometimes it gains access to 

 the spinal cord in the neck and produces the condition known as 

 " thorter-ill." 



From the fact that in some districts a very large number of 

 cases of sturdy are seen I have been led to form the opinion 

 that there must be some other host of the particular tape-worm 

 than the dog, and of all animals the fox is the most likely. 



The treatment of sturdy is often very successful, both by 

 simple tapping and by extraction of the bladder- worm, but it is 

 simple madness to allow a sheep to pine away with the disease, 

 as many do, until it is useless ; better by half kill it as soon as 

 it shows symptoms of the disease and make the best of it. 



As to the prevention of sturdy, the first and most important 

 thing to do is to carefully destroy the brains of affected sheep 

 instead, as is often done, throwing the " bleb " to the dog to eat ; 

 and secondly, to keep dogs as free from tape-worm as possible. 



Hvose is due to a round worm (the Strongylus filarius) which 



