628 COMMUNICABLE DISEASES OF LABORATORY ANIMALS 



INTESTINAL INFECTIONS 



Owing to the fact that infection of the rabbit's bile ducts with coccidia leads to 

 the formation of white or yellowish nodules or patches, this condition early attracted 

 the attention of observers. As early as 1854 Kolliker noted that the oocysts from the 

 intestine of the rabbit were smaller than those from the liver. In fact, it appeared 

 from an extensive series of tests conducted by Lucet, Reichenow,' and others that 

 the rabbit is liable to infection with two distinct species of Eimeria. Waworuntu,^ 

 who made a careful morphological and experimental investigation of the coccidia of 

 the rabbit, finds that the small form, Eimeria perforans, has always ellipsoidal and 

 often asymmetrical oocysts, while the shape of the Eimeria stiedae is ovoid. The 

 question of individuality of E. stiedae and E. perforans appears to have been placed 

 beyond doubt by Perard (1924)^ who has succeeded in obtaining pure strains of the 

 two species. The former, fed to young specially reared rabbits, produces only liver 

 lesions, which prove fatal to the young animals in twenty-eight to thirty days, while 

 the latter gives rise only to an intestinal infection, which kills the rabbits in nine to 

 fifteen days. He also describes a variety of the usual type, for which he proposes the 

 name E. perforans var. magna. The forms found by Bruce"" in acute and fatal enteri- 

 tis of young rabbits are either a mixed infection or a distinct species. No final deduc- 

 tions can be drawn from his report. A complete description of the life-cycle of the 

 rabbit coccidium may be found in a paper by Reich (i9i3).5 



It is well knovm that young rabbits are specially liable to infection, and they fre- 

 quently die in large numbers from acute hepatitis, which is caused by the active 

 multiplication of the coccidium in the biliary epithelium. When an outbreak occurs 

 in epidemic form, there may be a high rate of mortality. If the animals survive the 

 acute stage, the infection becomes of a chronic type and remains confined to certain 

 areas of the liver. In very old infections the coccidia disappear from the liver tumors, 

 which become fibrotic or even calcareous. The E. perforans remain confined to the 

 small intestines, which in the course of the acute stage are highly inflamed. In both 

 types of infection the virus is spread by oocysts, which either escape in the intestines 

 or are passed directly in the feces. Dissemination of very resistant oocysts may occur 

 after the death of the animals. Repeated attempts have been reported to treat 

 coccidiosis chemotherapeutically. Ottolenghi and Pabis'' had good results with sodium 

 antimonyltartrate (o.oi gm. subcutaneously). Preventive measures are, however, 

 much more satisfactory. A laboratory stock of rabbits can be kept free from cocci- 

 diosis by a systematic examination of the feces of any does which are used for breed- 

 ing purposes or animals which are brought in from outside. The cane-sugar flotation 

 and concentration method developed by Sheather^ gives excellent results. In case the 

 infection already exists among the stock animals, early separation of the young from 



' Reichenow, E.: Prowazek's Ilandb. d. Path. Prolozoen, 3, 1136. 1921. 



^Waworuntu, F. K.: Proefschr. Veeirlsenijk Hoogesch. Utrecht, 1924. 



3 Perard, C: Ann. de I'Insl. Pasteur, 39, 953. 1925. 



•» Bruce, E. A.: /. Am. Vet. M. A., 55, 620. 1919. 



5 Reich, F.: .Arch.f. Protislcnk., 28, i. 1913. 



^Ottolenghi, ])., and Pabis, E.: Centralhl. f. BakterioL, 69, 538. 1913. 



' Sheather, A. L.: J. Comp. Path. &' Therap., 34, 71. 1923. 



