92 DISEASES OP SHEEP. 



irritation of the skin ; the animal takes broader and shorter 

 steps with its hind feet, is unable to jump over elevated ob- 

 jects or walk easily over high steps, and breaks down in 

 the croup if it attempts to jump, so that it will tumble with 

 its fore feet, and even fall to the ground. The same takes 

 place if the sheep is raised from the ground and allowed to 

 drop, and it generally wags its head to and fro. The malady 

 augments from week to week, and with it the weakness of the 

 hind quarters, which becomes very apparent. The animal 

 can no longer gallop, but only trot (hence the name " trot- 

 ting disease"). If the sheep is forced to run quickly by a 

 dog, it generally falls down, and rises only with difficulty. ^ 



During the course of the disease the patient appears 

 stupid, the ears hang down loosely, and the palsy, which at 

 first befell only the hind quarters, becomes more general. 

 During the first few weeks the appetite remains good and 

 the patient does not lose flesh, but afterward it gradually 

 becomes lean, even if the appetite should remain unimpaired, 

 and finally death ensues, frequently after several months. 



Most sheep gnaw at their hind quarters, as has been re- 

 marked before, but this symptom is not present in every 

 case, and therefore not characteristic. The skin at the 

 parts which are gnawed is deprived of its wool, and if it 

 grow again, it is paler and coarser than before, and loses 

 its curl. Frequently the sick animals bite their skin until 

 it becomes bloody and a scab is formed on the spot, which 

 must not be mistaken for an eruption of the skin or for a 

 cause of the irritation and gnawing. 



The disease mostly attacks perfectly healthy, ^■'ell-fed 

 sheep, and appears more frequently in autumn than in any 

 other season of the year. Noble races are most liable to its 

 ravages, but it has been observed also in very common 

 country sheep. Sheep produced by crossing breeds seem 

 more predisposed to it than others. Death is the common 



