The two diseases have been long known in Scotland, and are the cause of serious loss to stock owners. Well-informed breeders have estimated the loss at not less than half a million sterling annually.

They resemble each other in being peculiar to certain districts, and in prevailing at certain seasons of the year. Louping-ill is most frequently met with in the southern and western counties, and chiefly affects sheep feeding on rough hill pastures. It occurs during May and early in June, and is most fatal amongst lambs, but old sheep, cattle, pigs, and even poultry are liable to it. A few sporadic cases are met with in October, especially in the Western Highlands, where it is known under the name of trembling. Braxy, known also as inflammation and sickness, is more general in its occurrence, and affects high and low pastures alike. It is more or less prevalent from October till February, and attacks sheep in good condition.