274 PARASITES OF THE DIGESTIVE APPARATUS. 



and to have been replaced by the parasites. This, however, is not really 

 the case. It is easy to prove by suitable dissection (after maceration of 

 the sections in 30 per cent, alcohol) that the coccidia are lodged in epithe- 

 lial cells which have become modified in shape and undergone hypertrophy 

 as the parasite has grown, whilst the nucleus has been pushed to one end 

 and undergone atrophy. 



Alongside the deceased glands may be found others which are quite 

 healthy. In the parts which are most markedly affected the interglan- 

 dular connective tissue is infiltrated and slightly thickened. Degoix has 

 never discovered coccidia in the cells of the intestinal mucous membrane 

 itself. The lesions may be met with throughout the large' intestine, but 

 are more numerous and grave as the rectum is approached. 



This disease is characterised by extensive inflammation, affecting the 

 entire mucous membrane of the large intestine, by more or less extensive 

 ulceration of this bowel, the ulcers being covered with muco-fibrinous 

 patches rich in coccidia, by localisation of the parasites in the epithelial 

 cells of the glandular cul-de-sac, by the appearance of the disease at a 

 special time of year and in special districts, where it assumes the form 

 of an enzooty, and by the fact that it always appears in the same pastures. 

 The mortality varies between 12 and 25 per cent, from year to year. 



Microscopic appearances. The protozoa which produce this disease 

 assume the form of ovoid cysts, varying in length from 18 to 25 /x, and 

 measuring at the widest part about 13 />t. They possess a hyaline envelope 

 whose existence is proved by its double contour line, and yellowish, 

 granular, highly refractile contents. This granular material does not 

 always occupy the whole of the cavity. At a certain stage of develop- 

 ment it collects towards the centre, forming a nucleus and leaving clear 

 spaces at the poles of the cell. At a later stage this nucleus divides into 

 four portions which afterwards separate. 



Treatment. The protozoa, in their cystic condition, are very resistant 

 to destructive influences. The most common natural cause of their de- 

 struction is drying in the open air. Unfortunately, in the localities where 

 the patients usually live, that is, filthy byres, wet pasturages, etc., this 

 destruction only takes place to a very limited extent. 



The disease can be attacked by prophylactic and therapeutic measures. 



Prophylaxis consists — firstly, in destroying the parasites contained in 

 the dejections by the free use of 3 per cent, sulphuric acid solution ; and, 

 secondly, in removing the young animals from infected fields during the 

 months between June and September. 



Therapeutic treatment comprises — firstly, stimulant applications 

 to the abdomen ; secondly, disinfection of the intestine by the adminis- 

 tration of salol, benzo-naphthol, very diluted solutions of creolin, etc ; 

 thirdly, intestinal irrigation by the administration of mucilaginous drinks 



