Pathological changes and local defense reaction occurring in spontaneous hepatic coccidiosis in rabbits (Oryctolagus cuniculus).

Abstract

Hepatic coccidiosis occurred in 56 rabbits belonging to different ages, sexes and breeds during the years from 2002 to 2005. Clinically, the severely affected rabbits showed decreased growth rate, anorexia, debilitation, listlessness, diarrhea, icterus and rough hair coat. Postmortem examinations revealed increased dirty dull straw colored peritoneal fluid. Hepatomegaly, with presence of discrete yellowish-white nodules of 1mm to 1 cm size on the surface and throughout the parenchyma, was seen. Smears from peritoneal fluid showed rafts of mesothelial cells. Impression smears from the liver nodules revealed presence of numerous developmental stages of Eimeria stiedae corresponding with the stage of the liver lesion. These were intermixed with sheats of hepatobiliary cells and inflammatory cells and the changes were reflective of the histological changes like biliary hyperplasia, cholangitis and vacuolar changes occurring in the liver. There was increase in the thickness of basement membrane with the advanced stage of the lesion. The basement membrane was up to 1-2 µm in thickness forming loop like structures over which resided hyperplastic biliary cells containing different stages of the parasite. Some thickened basement membranes were devoid of overlying cells which had desquamated and were present in the ductal lumens suggesting that the basement might have the local defensive role in warding off the coccidial infection. The basement membrane was positive for neutral mucopolysaccharides while as the inflammatory zones and biliary epithelia along with the gametogonic stages of the coccidium reacted positively to the increased acid mucopolysaccharides qualitatively. The results showed that the occurrence of hepatic coccidiosis in female rabbits coincided with the breeding and kindling periods. Direct wet mount smears from bile aid in diagnosis of the disease. Impression smears from the liver nodules might represent the histological changes in the liver. The basement membrane thickening might have a defensive role in warding off the coccidial infection.

Effects of Anticoccidial Drugs on Gross and Histopathological Lesions Caused by Experimental Rabbit Coccidiosis

“…Icterus was only seen in few severely affected rabbits probably because the main product of heme breakdown in rabbits is biliverdin as opposed bilirubin [7]. Other lesions reported in our study and that have been described in previous studies include deposition of bile pigment, obstructive jaundice in hepatic parenchyma and sinusoid dilatation [37,38,39]. The findings of this study show that diclazuril and sulfachloropyrazine drugs can be used therapeutically against rabbit coccidiosis once clinical signs presents and have high efficacy in reversing associated lesions.…”

Pathomorphological changes in parenchymatose organs of rabbits in case of chronic passalurosis

“…Кролівництво -перспективна галузь, одна з найприбутковіших у сільському господарстві. Негативним аспектом у розведенні кролів є те, що вони дуже сприйнятливі до багатьох інфекційних (Laakkonen et al, 2006;Kos'yanchuk, 2017) та інвазійних хвороб (Darzi et al, 2007;Sürsal et al, 2014;Okumu et al, 2014).…”