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

Abstract

Effects of commonly used anticoccidial drugs in treating lesions caused by intestinal and hepatic coccidiosis have not been described for anticoccidial-drugs used in Kenya. The objective of this study was to describe the effects of four anticoccidial drugs on gross and histopathological lesions caused by artificially-induced mixed Eimeria infection with inoculant dose of E. flavescens (20%), E. perforans (21%), E. intestinalis (9%), E. coecicola (4.2%), E. media (11.2%), E. piriformis (10.6%), E. stidae (16%), and E. Magna (8%). In a controlled laboratory trial, 60 weaner rabbits were randomly allocated to treatment groups A, B, C, D, E and F. Each group had 10 rabbits. Groups A and C served as uninfected-untreated and infecteduntreated control groups, respectively. Groups B, D, E and F were experimentally infected and treated with amprolium, diclazuril, sulfachloropyrazine, and trimethoprim-sulfamethoxazole, respectively. On day 30 post treatment, 3 rabbits from each treatment group were selected randomly and humanely euthanized for gross and microscopic lesion examination. Diclazuril and sulfachloropyrazine treatment groups had significantly minimal to no macroscopic and microscopic lesions. This was consistent with a high efficacy of the drugs in reversing intestinal and hepatic lesions of coccidiosis in rabbits. Rabbits from amprolium, trimethoprim-sulfamethoxazole and infected-untreated control groups presented with severe intestinal and hepatic gross lesions characterized by extensive hepatomegaly, numerous raised hepatic multinodular lesions and marked congestion of the intestines that indicated mild to no effect of the drugs in reversing hepatic and intestinal lesions. Microscopic lesions in rabbits treated with amprolium and trimethoprim-sulfamethoxazole had marked desquamation of intestinal and bile duct epithelium, distended and thickened bile duct, numerous coccidian parasites at different stages of development in duct epithelium and mature oocysts in the intestinal and bile duct lumens; as was in positive control group. Additionally, rabbits from the three treatment groups recorded higher intestinal and hepatic histological lesion scores.

Ameliorative Effect of Neem Leaf and Pomegranate Peel Extracts in Coccidial Infections in New Zealand and V-Line Rabbits: Performance, Intestinal Health, Oocyst Shedding, Carcass Traits, and Effect on Economic Measures

“…They also exhibited severe lymphocyte infiltration in 67% of the NZ white rabbits examined in a study performed in Iran [ 84 ] and in 7.7%, 9.1%, and 48.5% of the Rex, English, and NZ rabbit breeds examined in a study performed in Egypt, respectively [ 85 ]. Moreover, the highest macroscopic and microscopic lesion scores and total HIS in the examined intestines from the untreated infected NZ and VL rabbits in our study were in agreement with the data recorded in the intestines of California white and NZ rabbit breeds as a result of artificially induced mixed Eimeria infections [ 10 ]. These findings are attributed to the pathogenicity and pathology caused by oral inoculation with Eimeria spp.…”

“…Sections of paraffin-embedded tissue were stained with hematoxylin-eosin [ 46 ] and examined under a light microscope. The histopathological lesions of the jejunum in the different groups were scored on a scale from 0 to 4 according to the nature and extent of the infection [ 10 ] and used to calculate the total histological injury score (HIS) according to the method of Dommels [ 47 ], using the sum of the inflammatory lesions score (2×), the tissue destruction score, and the tissue reparation score.…”

“… # Macroscopic lesion in jejunum scoring according to [ 45 ]: 0 with no evident lesion, while a score of 3 was assigned to severely infected rabbits. ## Histopathological lesions in jejunum section were detected using a light microscope and scored from 0 to 4 in the different groups according to the nature and extent of the infection [ 10 ]. 0, Minimal (<10%); 1, Mild (11–20%); 2, Moderate (21–40%); 3, Marked (41–100%).…”

“…The above-described challenges demonstrate the urgent need to find natural alternatives to drugs and disinfectants with the ability to inhibit the growth of Eimeria , improve the immune system of rabbits, and increase animal productivity [ 6 , 10 ]. Recently, several plants have been tested for their ability to control coccidiosis [ 11 ].…”

Efficacy of Ficus sycomorus (Sycamore Fig) Extract on Intestinal Coccidiosis in Experimentally Infected Rabbits

“…The comparative histopathological lesion scoring in different groups was carried out by examining 5 high-power fields (×40), where 0, 1, 2, 3, and 4 scores denoted absence, minimal, mild, moderate, and severe lesions, respectively, in each examined region. The score assigned could be defined as the % of the affected area by the lesion [39,40].…”