Eimeria tenella: accumulation and retention of anticoccidial ionophores by extracellular sporozoites

Extracellular sporozoites of Eimeria tenella were incubated at either 25 or 40 C in the presence of ¹⁴C-lasalocid or ¹⁴C-narasin, both anticoccidial ionophores. Liquid scintillation analysis shows that both ionophores are accumulated by the sporozoites outside their host cell. The relative degree of retention was significantly different for the two incubation temperatures and the concentration of lasalocid retained was consistently greater than that of narasin.     

Eimeria meleagrimitis, E. adenoeides, and E. dispersa: Severity of infection and changes in the intestinal mucosa of the Turkey

Glucose and methionine were malabsorbed in some intestinal regions of turkeys infected with Eimeria meleagrimitis, E. adenoeides, or E. dispersa. The decrease in absorption was not always related to the numbers of parasites in the cells or the extent of damage to the mucosa. With E. adenoeides, malabsorption was found in the jejunum even though parasites were not present. Conversely, with E. dispersa, no malabsorption was observed in the duodenum even though light microscopy showed numerous parasites. In many intestinal regions, damage to the mucosal surface visible with scanning electron microscopy (SEM) was slight or absent, although malabsorption was marked. No changes were noted with SEM in the structure and orientation of the brush border in these regions. Villar height was significantly reduced in the regions of heaviest infection when intestinal damage was visible. Conversely, the crypts of Lieberkühn were often two or three times as deep in infected poults as in uninfected poults. In general, no differences were found in the thickness of the circular and longitudinal muscle layers between the infected and uninfected poults. The dry weight of the intestinal tissue was less from infected poults than from uninoculated controls and was related to both region of the intestine and severity of the infection.     

Eimeria stiedae: experimental infection in rabbits and the effect of treatment with toltrazuril and ivermectin

The aim of this study was to investigate the clinical, haematological, biochemical, lipid peroxidation, ultrasonographic and pathologic findings in hepatic coccidiosis induced by Eimeria stiedae in rabbits, and also to compare the treatment effects of both toltrazuril and ivermectin separately and in combination. In this study, 56 rabbits were divided into eight groups. The first group was designated as healthy control group. Rabbits were infected with 40.000 sporulated oocysts of E. stiedae. Groups 2, 3, 4, 5, 6, 7 and 8 were allocated as the infected control group, infected+toltrazuril-treated group, infected+ivermectin-treated group, infected+toltrazuril+ivermectin-treated group, non-infected+toltrazuril-treated group, non-infected+ivermectin-treated group, non-infected+toltrazuril+ivermectin-treated group, respectively. Haematocrit, Haemoglobin and MCV values as well as percentage of lymphocyte decreased in Groups 2 and 4 whereas leucocyte counts and percentage of granulocyte leucocyte increased. Serum GGT, ALT and AST activities increased but albumin value decreased. Plasma MDA concentrations increased whereas erythrocyte CAT, GSH-Px, and SOD activities decreased. Mean oocyst numbers in per gram faeces (epg values) increased in both groups during the study. Ultrasonographic examination revealed that the liver was enlarged and had hyperechogenic parenchyma. Bile ducts were dilated and hyperechogenic and the gall bladder was dilated. The livers of these animals were enlarged and typical macroscopic and microscopic findings of coccidiosis were present. Treatment with toltrazuril and toltrazuril+ivermectin combination were highly effective in reducing faecal oocyst output in infected rabbits. Haematological, biochemical and lipid peroxidation parameters and, ultrasonographic findings of the liver were close to control values for Groups 3 and 5. Necropsy of these animals showed no visible lesions related to hepatic coccidiosis although a few oocysts were detected in the bile duct epithelial cells.