SYMPTOMS AND DIAGNOSIS 37 



diarrhoea and paralysis, and causing death in seven to 

 eight hours. 



M'Gowan and Rettie, in the four cases of scrapie 

 mentioned, found, post mortem, no naked-eye lesions 

 except strongylosis of the lung and alimentary canal. 

 The extent of this invasion of strongyles is not men- 

 tioned. The lesion common to all the animals was 

 a marked sarcosporidiosis, which was only seen on 

 microscopic examination. The parasites were found 

 in the panniculus carnosus, in the muscles of the jaws, 

 pharynx, larynx, neck, pelvis, and hind hmbs ; also in 

 the intercostals, heart, oesophagus, and diaphragm. 

 Though carefully sought for, no acid-fast bacilli were 

 found in the intestinal canal or in the mesenteric 

 glands. 



In swine the sarcocyst infection is said to cause 

 paralysis of the hindquarters, stiffness, and cutaneous 

 eruption ; but none of these symptoms, mentioned by 

 various writers, can be said to be characteristic, as 

 they may be met with in so many other diseases of 

 swine. 



However, it may be shown by future investigations 

 that the skin lesions and pruritus are due to a sarcocyst 

 infection, and that diarrhoea and emaciation are the 

 only symptoms caused by the acid-fast bacilli in the in- 

 testines of sheep, as in cattle. The bacterial infection 

 of the bowel may assist the sarcocysts in becoming 

 dangerously numerous, and these parasites may lower 

 the power of resistance in the sheep so that the bacilli 

 can establish themselves. M'Gowan and Rettie's 

 suggestion as to the pruritus, etc., being caused by 

 the sarcocysts bears out Stockman's theory that the 

 enteritis and the skin lesions in these cases are distinct. 



Diagnosis (Bacteriological).— Since the recognition 

 of Johne's disease is becoming more general in Great 



