Coccidiosis in European rabbit (Oryctolagus cuniculus algirus) populations in the Iberian Peninsula

Hepatic Coccidiosis in Wild Rabbits in Greece: Parasite Detection on Liver Imprints and the Associated Biochemical Profile

(1) Background: Rabbit hepatic coccidiosis, caused by Eimeria stiedae, is a devastating disease with high morbidity and mortality rates. The disease is well described in rabbits, but little is known about E. stiedae infection in wild rabbits. In this study, we investigated the presence of E. stiedae infection in wild rabbits from the island of Lemnos, Greece, where this species is overpopulated, and the effects of infection on common hepatic biomarkers. (2) Methods: We used liver impression smears to detect the coccidian oocysts, and we defined the liver biochemical profile of the infected individuals. (3) Results: Overall, 13.3% of the liver imprints examined were positive for the presence of coccidial oocysts. The activities of liver enzymes, that is, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and glutamyltransferase (GGT), as well as globulins (GLOB), were increased while the concentrations of albumins (ALB), total proteins (TP) and the albumin to globulin (A/G) ratio were decreased in the infected individuals compared to the non-infected ones. (4) Conclusions: This study adds to the current knowledge on the pathogens affecting wild rabbits and those circulating in this population on the island of Lemnos, Greece. Moreover, we showed that E. stiedae infection exerts pathological effects on the hepatocyte integrity and liver function of wild rabbits, as reflected by the abnormal values of liver injury and dysfunction biomarkers.

Effect of the drug “Degelm-14” on spontaneously infected chickens with eimeriosis

The studies show that when using the preparation "Degelm-14" after infection of birds, the histological structure in most of the studied organs was gradually restored. In the glandular stomach and small intestine on the 22nd day after application of the studied preparation the microstructure of the organ recovered completely. Microstructural changes in the cloacal pouch and spleen after application of Degelm-14 indicated restoration of the proliferative activity of the cells of the germinal centers. In the liver, at the final stage of the study, there were no signs of metabolic disorders in hepatocytes, and the dark pink coloration of their cytoplasm indicated an increase in synthetic processes in the cells of the organ parenchyma. But in the kidneys there were still observed signs of impaired glomerular filtration, regulating the function of the organ.

INTENSITY OF INVASION IN EMERIOSIS OF RABBITS IN DIFFERENT METHODS OF KEEPING

One of the important problems in raising rabbits is eimeriosis, regardless of the method of maintenance. The disease affects animals of all ages, causing weight loss, feed conversion, morbidity and death. The aim. Study of the prevalence and diagnosis of rabbit eimeriosis by different housing technology to improve methods of disease control. Methods. The experiment was conducted during 2017–2019 in farms with different capacities in four regions of Dnipro, Zaporizhia, Kharkiv and Sumy. A total of 20 farms for keeping rabbits of different breeds were surveyed. Results. Studies of rabbit farms on business and private ones found that the most common infestation was with the following species of eimeria: Eimeria perforans, E magna, E. media, E. irresidua, E. piriforms and E. іntestinalis. It is proved that the extensiveness of rabbit infestation when kept in farms in metal cages, under the conditions of sanitary and hygienic regime and timely disinvasion of premises, was in the range of 42–15 % in autumn-winter period, and 19–6 % in spring-summer. According to the survey of homestead farms, rabbits kept in wooden cages on deep litter, the level of invasion in the autumn-winter period was 100–56 % and in the spring-summer – 70–29 %. Conclusions. Keeping rabbits in metal cages in compliance with sanitary and hygienic standards and timely disinvasion reduces the level of extensiveness of the invasion.

DEVELOPMENT OF PREVENTING MEANS FOR RABBITS’ COCCIDIOSIS

The great problem of rabbits breeding today is coccidiosis. An agent of the disease spreads not only through ill animals and is preserved well in the external environment. Oocysts of coccidia live in cells for a long time, so even temporal vacation of an accommodation between placing of rabbits doesn’t prevent infection. It was experimentally proved, that there is a very limited spectrum of means that are coccidiostatics. For preventing and controlling rabbits’ eimeriosis, coccidiostatic means were tested. It is very difficult to annihilate coccidia in vivo and in vitro because of peculiarities of their construction. The aim of the first experiment was to determine the influence of an acidifier Cronocyde L and its components on oocysts of coccidia that allows to determine an optimal composition and concentration of the preparation. At conducting the research, there was used the flotation method of Fulleborn and McMaster one for calculating oocysts. The aim of the second experiment was to determine the influence of the acidifier Cronocyde L standard and Cronocyde L concentrate (1 ml/1l of water) on the intensity of the living mass increment in rabbits. For that there were used clinical, hematological, zootechnical and microscopic methods. Optimal results in the experiment were obtained at using Cronocyde L concentrate and Cronocyde L standard in concentration 0,1 %: maximal growth and health status of rabbits, biochemical indices of blood serum were within the physiological norm. It testifies to the effectiveness of this preparation at eimeriosis of rabbits and to harmlessness for them. The studies, realized under laboratory conditions, prove the effectiveness of the offered means.

Detection of rabbit Haemorrhagic disease virus 2 during the wild rabbit (Oryctolagus cuniculus) eradication from the Berlengas archipelago, Portugal

BACKGROUND

In the regular wildlife monitoring action carried out in the summer of the past few years at the Berlenga Island, wild rabbits (Oryctolagus cuniculus) have been repeatedly found dead. However, the origin of those deaths was never investigated. Our aim was to investigate the cause of death of 11 rabbits collected between April and May 2016.

RESULTS

While screening samples from rabbit carcasses for the major viral rabbit pathogens, five tested positive to RHDV2 but all were negative for RHDV and myxoma virus (MYXV). For six RHDV2-negative specimens, emaciation and parasitism were considered the most probable cause of death. Lesions identified in the RHDV2-positive rabbits included non-suppurative diffuse hepatic necrosis and pulmonary lesions varying from congestion and oedema of the lungs to interstitial pneumonia. Sequencing analysis of the vp60 gene obtained from two specimens showed identical vp60 sequences. Comparison with other known RHDV2 strains from public databases through BLAST analysis revealed a closer similarity with strains from Alentejo collected during 2013. Maximum Likelihood and Bayesian phylogenetic analysis showed that the 2016 strains from the archipelago have a higher resemblance with a group of strains mostly collected in the South of Portugal between 2013 and 2014.

CONCLUSION

The results suggest that RHDV2 may have been introduced on the Berlenga Island a few years ago, having evolved separately from mainland strains due to insularity.