Histopathological changes in pigs infected with ileitis

O.M Yermolenko,I.Yu Mushtuk,O.Y Ayshpur

doi:10.15421/2020_170

Abstract

Nowadays, the ileitis (proliferative enteropathy of pigs) is one of the most common gastrointestinal diseases. The intracellular bacterium Lawsonia intracelluaris causes several forms of the disease. Histological examinations are the important stages in diagnosing and detecting profound pathological changes in sick pig organs, decreasing their productivity and causing the deaths. Swine proliferative enteropathy (SPE) has reported for the Ukraine since 2008. For SPE the early diagnostics with different test systems is relevant. We evaluated the sick, forcibly killed and dead piglets of different ages in Ukrainian pig farms during 2018-2019 in animal fattening groups. Materials were taken from piglets aged 120-150 days in farms where the ileitis was diagnosed. To assess the complex of pathological and anatomical changes detected during autopsies of piglets, V.P. Shishkov’s methods were used. Thus, we revealed a characteristic morphology of proliferative lesions. We believed that the histological examination can serve as an important diagnostic method and an alternative to direct isolation of Lawsonia intracellularis, which is very difficult to cultivate. We determined that the histopathological changes in pig organs indicated a chronic effect caused by animal pathogen. We revealed that Lawsonia intracellularis caused the profound pathological changes in pig digestive tracts, which affected the functioning of all organs and tissues of animals and lead to severe disease and possible animal death. We suggested that the histological examination is an important step in diagnosing and detecting profound pathological changes in the organs of sick pigs, which caused the decrease in their productivity and deaths.

Highlights

IntroductionIleitis (proliferative enteropathy of pigs), caused by the obligate intracellular parasite, the bacterium Lawsonia intracellularis, is the most common intestinal infection worldwide, affecting piglets in the rearing and fattening pigs
Ileitis, caused by the obligate intracellular parasite, the bacterium Lawsonia intracellularis, is the most common intestinal infection worldwide, affecting piglets in the rearing and fattening pigs
These results verified the decease increasing in domestic pig farms, especially during the period of fattening, which caused significant economic losses (Ayshpur et al, 2019)

Summary

Introduction

Ileitis (proliferative enteropathy of pigs), caused by the obligate intracellular parasite, the bacterium Lawsonia intracellularis, is the most common intestinal infection worldwide, affecting piglets in the rearing and fattening pigs. The disease occurs in four different forms, namely: regional ileitis, intestinal adenomatosis, hemorrhagic enteropathy, necrotic enteritis It is characterized by intestinal disorders and progressive weight loss in pigs (Lawson et al, 2000; McOrist et al, 2006; Karuppannan & Opriessnig, 2018; Leite et al, 2019). In 2019, our scientists conducted a solid-phase blocking ELISA to detect specific antibodies to the pathogen Lawsonia intracellularis (Ayshpur et al, 2019).A total of 653 serum samples of different age pigs groups from 17 domestic farms were studied. Seropositive pigs were found in all the farms, which were researched, namely, among sows 74.0%, replacement gilts - 79.6%, piglets for rearing 10.5% and pigs for fattening - 55.3%. Ileitis diagnosis is based on clinical and epizootiological analysis, microscopic, serological methods, immunofluorescence method (IFA) and immunoperoxidase monolayer assay (IPMA) for the detection of the antibodies of Lawsonia intracellularis, detection of pathogen DNA by polymerase chain reaction, immunohistochemical analysis (IHC) and histopathological analysis (Bonaet al., 2003; Hardge et al, 2006; Ayshpur et al, 2019; Resendeet al., 2019; Visscheret al., 2018; Guedeset al., 2017; Pérez Gaudioet al., 2018; Yeh& Ga, 2018)

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Conclusion