30 JOHNE'S DISEASE 



Differential Diagnosis (Clinical). — The causes that 

 may give rise to diarrhoea in cattle are very varied, 

 and include errors in feeding, frosted roots, mouldy 

 corn or hay, irritants such as ricin or sand in feeding 

 cakes, and various mineral poisons ; also intestinal 

 strongylosis, often associated in young stock with 

 bronchial strongylosis ; and, lastly, coccidiosis and 

 tubercular enteritis. 



The acute febrile conditions, such as anthrax, rinder- 

 pest, and mahgnant catarrh, may also give rise to diar- 

 rhoea, but need not here be considered. 



In some parts of the country certain land seems 

 to predispose to diarrhoea in cattle pastured on it. 

 In Somerset such land is known as " teart " land or 

 " scouring land." The exact reason for the effect that 

 this land has on the animals is not known ; but with 

 such land the diarrhoea occurs when the animals are 

 turned out, and ceases when they are removed. The 

 disease also attacks a number of animals at the same 

 time. 



The irritants, which arise from unsound food, 

 poisoning, etc., can be considered together. They are 

 naturally the first causes to be sought for by a prac- 

 titioner in conducting an inquiry on a farm. There 

 will probably be several animals attacked at once. 

 The symptoms as a rule are acute, and the diarrhoea is 

 well marked before the animal has suffered sufficiently 

 from toxic effects to become emaciated. It may be 

 accompanied by fever, loss of appetite, and cessation 

 of rumination ; and an examination into the dietetic 

 and hygienic management of the farm will soon reveal 

 the cause. 



There remain to be considered strongylosis, cocci- 

 diosis (psorospermosis), and tubercular enteritis. 

 Miessner and Trapp have mentioned a case of sarcoma- 



