156 DISEASES OP THE BEAIN AND NEKVOUS SYSTEM. 



thofer, Koll, Hamilton, Profs. Williams, Dick and Young 

 have conducted careful studies and experiments as to the origin 

 of this disease without any definite results. The history of loup- 

 ing-ill shows that it has existed in epidemic form many times in 

 Scotland — notably on the Silurean strata, extending from the 

 Hebrides to the Southern extremity of Dumfriesshire. Waldie 

 of Jedburg long ago suggested that louping-ill was due to liming 

 the soil, and that it disappeared 'when the lime became ex- 

 hausted. — Steele. Dr. Hamilton suggested that the disease was 

 inflammation of the brain and spinal cord. Profs. Dick and 

 Eobertson both considered that smut on grasses caused the dis- 

 ease; coarse withered grasses for food are also generally asso- 

 ciated with this disorder. Ticks have also been considered to 

 be the cause, supposedly carrying some specific poison and in- 

 fecting the sheep, but this theory seems untenable, as the dis- 

 ease has been known to appear in pigs, where the idea of tick 

 infection would have to be discarded, it being more probable 

 that it originated in them from eating sheep offal from animals 

 which had suffered from the malady. Overstocking, poverty, 

 dry easterly frosty winds in April and May are also said to be 

 productive of louping-ill to a great extent — in fact, almost every- 

 thing has been claimed to be a cause, showing certainly a great 

 diversity of opinion as to the origin of this obscure complaint. 



Symptoms. 



Trembling of the hind parts, twitching of the muscles. In 

 acute cases, the pulse is accelerated, skin dry and hard, catarrh 

 is often present, emaciation sets in, the sheep grinds its teeth, 

 commences to pine, and finally death supervenes. Kichthofer 

 claims that the disease has only developed and become hereditary 

 since the introduction of Merinos, and Roll also classes it as a 

 disease of high-bred, fine-wooled sheep. In the early stages of 

 the disease the sheep are in poor condition and going back, the 



