36 JOHNE'S DISEASE 



From this description — a translation of Nocard's 

 article — it is evident that tubercular enteritis is not 

 common. Examination of the faeces would, of course, 

 be useless, as, if acid- fast bacilli were found, it would 

 be impossible to decide whether they were Koch's or 

 Johne's micro-organisms. An application of the tuber- 

 culin test should give a positive result, and as the 

 disease is very unlikely to be cured or to show 

 any improvement, immediate slaughter is advisable. 

 The symptom of obstinate constipation, noted by 

 Nocard, is important, as we have been unable to 

 discover any record of such a complication in Johne's 

 disease. 



An interesting point has been raised by the dis- 

 covery of M'Gowan and Rettie that four sheep suffer- 

 ing from scrapie and examined by them were heavily 

 infected with Sarcocystis tenella. To a greater or less 

 extent all the domesticated animals are from time to 

 time found to be affected with sarcosporidiosis, and 

 occasionally the parasites are sufficiently numerous 

 to give rise to symptoms. Moule has found 98 per 

 cent, of cachectic sheep and 34 per cent, of healthy 

 sheep infected. He has also found the parasite in 

 46 per cent, of goats examined, and in 37 per cent, 

 of oxen condemned for extreme emaciation. Besnoit 

 and Robin, quoted by Gray, found a sarcocyst present 

 in great numbers in a ten-year-old cow which showed 

 marked skin lesions, thickening, depilations, etc. 

 Though they were unable to inoculate the disease, 

 they succeeded in causing death in a rabbit by injecting 

 subcutaneously a glycerine extract of some of the 

 larger lesions. Gray states that sarcocystin, consisting 

 of a glycerine extract of the parasites, was found by 

 Laveran and Mesnil, and also by Pfeiffer, to be toxic to 

 rabbits, producing, when injected under the skin. 



