Coccidian Enteritis in Cattle. 263 



Causes. Predisposing causes embrace such as induce weakness 

 or debility, youth, low condition, cold intemperate weather, ex- 

 treme heats, musty or spoilt fodders. 



The essential cause, the coccidium, appears to be taken in with 

 food or water as sucking calves are largely exempt. The para- 

 site is found in the gastric and intestinal epithelium of the dis- 

 eased animals, in numbers proportionate to the severity of the at- 

 tack, being very abundant when the disease is at its height, 

 diminishing during convalescence, and disappearing entirely on 

 recovery. Two species are found in this disease. 



Coccidium Oviforme is 40 to 50/u. long by 22 to 28/u, thick, 

 ovoid, with a double outlined limiting membrane inclosing a re- 

 frangent protoplasm with a nucleus two or three times as large as 

 that of an epithelial cell, and staining with hsematoxylon or ani- 

 line colors. The young coccidia appear as round granular proto- 

 plasmic masses, without a capsule but provided with a nucleus. 

 At first of a diameter of 9 to 10//. they increase to 26/*. retaining 

 the spherical form and acquiring the membrane of the mature 

 parasite. As it grows the protoplasm separates from the wall 

 and forms a globular nucleated mass, which after fifteen days di- 

 vides into two and later into four masses or sporoblasts. Each 

 sporoblast in its turn divides into two falciform corpuscles lying 

 in contact but in an inverse sense to each other. Each of these 

 under favorable conditions becomes a new amceboid individual 

 capable of invading an epithelial cell and passing through the 

 same stages of development as its predecessor. 



The coccidium oviforme is found in the epidermis in cutaneous 

 psorospermosis of birds, and in the coccidian hepatitis in rabbits. 



Coccidium Perforans. In its mature form this is 25/u. to 35/t 

 long, by 14/u. to 20/* broad. Its different stages of evolution are 

 essentially the same as for the Coccidium Oviforme. It is a cause 

 of intestinal Coccidiosis in both dog and rabbit as well as in cattle, 

 usually killing the rabbit in from eight to ten days. 



Lesions. In the first reported cases in calves in 1877 (Proger 

 and Zurn), there was catarrhal inflammation of the upper air 

 passages as well as the bowels. There was thickening, redness 

 and desquamation of the abomasum near the pylorus of the small 

 intestine and colon. In the intestines there were patches of 

 thickening and softening of the mucosa and miliary ulcers with 



