STATE HYGIENE 509 



in the Midlands was discovered to be due to a surveyor's 

 measuring chain. An observation in the measurement 

 of a healthy farm had to be repeated, after the chain 

 had been employed in measuring one where the disease 

 existed. 



In the four outbreaks which have occurred in England 

 since 1891, the germs of the disease have been imported 

 from abroad, but the most rigid inquiry has failed to 

 explain some of the outbreaks. Professor Bang of Copen- 

 hagen suggests that birds may easily carry the infection 

 on their feet from place to place ; this is supported by 

 Simmonds' opinion given above, the story of the sur- 

 veyor's chain, and the evidence of the Chief Veterinary 

 Officer of the Board of Agriculture, quoted on p. 495, of the 

 introduction of the disease by ships from non-affected 

 countries, through using head-ropes from cattle which 

 had previously been infected at the Cattle Market at 

 Deptford. 



The animals affected by Foot and Mouth Disease are 

 cattle, sheep, pigs, and occasionally the human subject. 

 The disease has a short incubative period, the symptoms 

 are evident within a week, and the diagnosis is easy. The 

 affection of cattle and sheep simultaneously, and the highly 

 contagious character of the disorder admit of little doubt 

 in diagnosis ; as Professor McFadyean tersely puts it, ' in 

 cattle a sore mouth and lameness is a combination only 

 met with in Foot and Mouth Disease.'* 



The same authority points out three diseases of sheep 

 which may be mistaken for foot and mouth — -viz., contagious 

 foot rot, malignant aphtha, and an eruption on the face and 

 limbs of sheep, known in Scotland as ' Orf,' and he points 

 out as a differential diagnosis that foot rot only as a rule 

 affects one foot, malignant aphtha affects only ewes and 

 very young lambs, while in ' Orf ' the eruption is mainly on 

 the face, nostril, and lip, and never inside the mouth ; 

 further, the disease, though contagious to sheep, is not so 

 to cattle. 



* Journal of the Boyal Agricultural Society, vol. Ixii., 1901. 



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