CARP COCCIDIOSIS - CLINICAL AND HEMATOLOGICAL OBSERVATIONS OF CARP INFECTED WITH GOUSSIA-CARPELLI

To examine the pathogenic capacity of Goussia carpelli, a gut-dwelling coccidian parasite of common carp Cyprinus carpio, hematological para meters were recorded from carp following a laboratory-induced infectio n with this parasite. With the development of the parasite, serum sodi um and protein levels decreased, thus indicating an ion loss and the h ydration of blood plasma in infected fish. On Days a and 11 post expos ure (PE) to the parasite, Aeromonas spp.-like bacteria were detected i n the liver and the spleen of 8 infected carp out of the 10 carp sampl ed, while uninfected control carp remained bacteria-free. On these dat es, infected carp were listless, and their intestines appeared dilated and were filled with a whitish-yellow gelatinous content. In intestin al scrapings, gamogonic and sporogonic developmental stages of the coc cidia were found. Differential white blood cell counts of peripheral b lood leukocytes showed an increase in granulocyte numbers on Days 11 a nd 14 PE. On Days 21 and 28 PE, when the carp had already excreted mos t of the oocysts, a clear leucocytosis was found. Owing to the osmotic challenge of infected carp, which is caused by ion loss and plasma hy dration, and to the invasion of opportunistic bacteria, the infection of carp with G. carpelli should be taken as a serious pathogen affecti ng stressed or juvenile fish.