760 Trotting Disease. 



Ill spite of the fact that the appetite remains good up to 

 the end, emaciation, anemia, or hydremia, becomes more and 

 more pronounced. Finally the weakness of the hind quarters 

 becomes so great that the animals lie on the ground as if para- 

 lyzed, and emit hoarse groans. There is an offensive discharge 

 from the nose and mouth, but they still gnaw places that they 

 can reach. Finally they die from complete exhaustion. 



Course and Prognosis. In the great majority of cases the 

 onset of the disease is insidious and its progress slow. There 

 may be apparent improvements from time to time, but the 

 disease terminates fatally in two to four months. In very oc- 

 casional cases the animals are in a condition of utter prostra- 

 tion within four to six weeks. The course of the disease tends 

 to be more rapid in summer than in winter, and in young ani- 

 mals than in adults. 



Eecovery is very exceptional and when it occurs it is in 

 the early stages of the disease. 



The disease spreads very slowly, but in some cases the 

 spread has been so rapid that in the course of a few years the 

 profits have been out-balanced by the losses sustained, so that 

 continued occupation of the farm becomes impossible. 



Very occasionally there is a sudden outbreak of the disease 

 on a farm previously free and within a short period great losses 

 may be experienced, especially among the young lambs. 



Diagnosis. Timidity, motor disturbances and especially 

 the peculiar gait, and the intense pruritus combine to form a 

 characteristic collection of symptoms. 



The cardinal symptoms mentioned are not presented by 

 every case, but since a number of animals are always affected 

 at the same time the incomplete series of symptoms presented 

 by any individual animal can often be completed by examina- 

 tion of other animals. Diagnosis is most difficult where only a 

 few animals are affected, as in the case of newly purchased 

 rams, and when the symptoms presented by such cases are not 

 characteristic. More extensive observations will furnish evi- 

 dence as to the nature of the disease. 



The disease may be distinguished from other diseases char- 

 acterized by pruritus, and in particular from scab, by the fact 

 that the skin appears to be healthy save for the lesions caused 

 by the rubbing. In other diseases no motor disturbances are 

 observed. Canurosis has often been mistaken for this disease, 

 the development of cysts in the vertebral canal sometimes caus- 

 ing sacral paralysis, but in coenurosis there is never any timid- 

 ity, trembling or pruritus. 



Treatment. Up to the present no satisfactory treatment 

 has been devised, and the animals should be slaughtered as 

 early as possible. 



