THE TELOSPORASIDA AND THE COCCIDIA PROPER 



201 



are unknown, 

 to 2 days. 



The sporulation time is 1. 5 



Life Cycle : Unknown. 



Pathogenesis : According to Tsunoda 

 (1952), this species may be slightly to 

 moderately pathogenic, causing a diphther- 

 itic enteritis. 



COCCIDIOSIS IN DOMESTIC RABBITS 



Epidemiology : The most important 

 species of rabbit coccidium is Eimeria 

 stiedae, which occurs in the liver. All 

 the other species are found in the intestine. 

 Of these, the most important are E. 

 residua, E. magna, E. media a.nd E. per- 

 f oralis. Kheisin (1957) has assembled in- 

 formation on the localization of the intes- 

 tinal species. 



Coccidiosis is primarily a disease of 

 young rabbits; adults are carriers. Rab- 

 bits become infected by ingesting oocysts 

 along with their feed or water. The se- 

 verity of the disease depends upon the 

 number of oocysts they ingest and also 

 upon the species involved. Mixed infec- 

 tions are the rule, infections with a single 

 species usually being seen only under 

 laboratory conditions. Crowding and lack 

 of sanitation greatly increase the disease 

 hazard. 



Some of the coccidia of the domestic 

 rabbit {Oryctolagus cnniculiis) also occur 

 in cottontails {Sylvilagiis spp. ). Some 

 have also been reported from jack rabbits 

 and hares (Lepus spp. ). However, after 

 reviewing the cross-transmission studies 

 carried out to date, Pelle'rdy (1956a) con- 

 cluded that, except for E. stiedae, none 

 of the coccidia of jack rabbits and hares 

 occur in domestic rabbits and cottontails, 

 and none of the coccidia of the latter two 

 genera occur in Lepus. If this conclusion 

 is confirmed, the listing above of Lepus 

 as a host of E. niagna, E. perforans, 

 E. media and E. irresidua would be in- 

 correct. Further cross-transmission 

 experiments are needed to settle this 

 matter. 



Diagnosis : Liver coccidiosis can be 

 diagnosed by finding the characteristic 

 lesions containing coccidia. Intestinal 

 coccidiosis can be diagnosed by finding 

 the coccidia on microscopic examination. 

 However, the mere presence of these 

 parasites in a case of enteritis does not 

 mean that they caused it. Many rabbits 

 carry a few coccidia without suffering any 

 noticeable effects. In a 3-year study of 

 mortality among hutch-raised domestic 

 rabbits in California, Lund (1951) consid- 

 ered coccidiosis to be the cause of enter- 

 itis in only 80 out of 1541 affected animals. 



Treatment : Some of the sulfonamides 

 have been found helpful in preventing coc- 

 cidiosis if given continuously in the feed 

 or drinking water. Succinylsulfathiazole, 

 sulfamerazine or sulfamethazine mixed 

 with the feed at the rate of 0.5% have been 

 recommended (Horton-Smith, 1947; Ger- 

 undo, 1948), as have been 0.02 to 0.05% 

 sodium sulfaquinoxaline or sodium sulfa- 

 merazine in the drinking water. Lund 

 (1954) found that the administration of 

 0. 03% sulfaquinoxaline in the feed con- 

 trolled E. stiedae infections effectively if 

 begun not more than 4 days after exper- 

 imental infection. The drug was not com- 

 pletely effective at this level, but it did 

 give practical control. Lund stated further 

 that this drug had not been found to harm 

 rabbits when fed continuously. 



However, long-term, continuous feed- 

 ing of such drugs is not particularly de- 

 sirable, nor is it usually necessary. It 

 has been the usual experience with poultry, 

 and there is evidence that the same thing 

 is true with rabbits (see Horton-Smith, 

 1947), that if the hosts are exposed to 

 coccidiosis during the drug-feeding period 

 (as they usually are), an aborted infection 

 occurs which is sufficient to induce immun- 

 ity. The drug can then be safely stopped. 



Prevention : Coccidiosis can be pre- 

 vented by proper management (see Lund, 

 1949). Feeders and waterers should be 

 designed so that they do not become con- 

 taminated with droppings, and should be 

 kept clean. Hutch floors should be self- 

 cleaning or should be cleaned frequently 



