240 Report on the Contagious and 



Where the disease is allowed to take its course unchecked it is commonly 

 the case that a large percentaiie of deaths occur, and at best the affection 

 which is naturally communicated is never so mild as that produced by 

 inoculation, while the extension of the disease to the whole of the flock 

 occupies a very considerable time, prolonging therefore the risk of the com- 

 munication of the infection to tlie neighbouring flocks. 



The argument against inoculation is the obvious one, that it keeps up the 

 disease in the infected district for a certain period, but the same statement 

 might be correctly made of the negative course, which consists in allowing 

 tlie infection to pass naturally to the susceptible animals. 



Experience justifles the conclusion that sheep-pox when it appears in a 

 flock will extend gradually to nearly all the animals that have been exposed 

 to its influence, and under these circumstances, if it is determined not to 

 adopt the stamping-out system, it will be desirable to hasten the progress of 

 the disease and moderate its virulence by having recourse to inoculation. 

 The disease thus induced appears usually in a mild form, and is attended 

 with very little loss of life, while the animal is secured from a second attack 

 as completely as it would have been if it had taken the malady in a natural 

 way. Inoculation to be successful must be performed by a skilled person 

 who is well acquainted with the character of lymph which should be employed 

 and the means of introducing it into the animal's system. It has happened 

 on some occasions when inoculation has been improperly performed, and 

 especially when a bad quality of lymph has been used, that very serious 

 effects have resulted. This, however, by no means detracts from the value of 

 the operation when skilfully done. 



The inoculated flock will require all the veterinary care which would be 

 given in the case of the animals having taken the disease in the natural way, 

 and in the event of any of the inoculated animals having the disease in a 

 severe form, which, however, is not to be nppi'ehended, it will be desirable to 

 isolate them in order that they may be submitted to medical treatment, 

 which in the case of the rest of the flock will be altogether unnecessary. 



The advantageous results of inoculation are thus summed up in a report, 

 which was issued by Mr. Marson and Professor Simonds in June, 1864 : 

 " It gives security against a second attack of sheep-pox ; it limits the period 

 of the existence of the disease in the flock ; it mitigates the severity of the 

 malady ; it saves the lives of many animals which, otherwise, would be 

 sacrificed ; and it controls the extension of the disease, as one confluent 

 natural case does more to dift'use the poison than probably 50 ordinary inocu- 

 lated cases would do.'" The mortality from the inoculated disease, when 

 compared with the natural, is, on the average, as three per cent, in the one 

 case is to 50 per cent, in the other. 



Sheep-Scab. 



Although this disease is included in the contagious and infectious diseases 

 enumerated in the 6th section of the Act, it is not a contagious malady in the 

 ordinary acceptation of the term. Sheep-scab is in reality a local disease, 

 consisting chiefly of irritation followed by exudation on the surface of the 

 skin consequent u^xm the ravages of a small acarus closely allied to the 

 itch insect of the human subject. 



All kinds of farm stock are liable to the invasion of parasites \\hich produce 

 more or less irritation of the surface ; the mange of the horse and the ox- are 

 of jirecisely the same character as scab in sheep, but in both these animals 

 they occur to a much less extent. Mange in the horse is generally confined 

 to animals in very poor condition, and which are usually subject to consider- 

 able hardship. It is only by accident that the affection appears in a well- 

 managed stable, and its existence is immediately detected in consequence of 



