Necrotic enteritis due to simultaneous infection with Isospora suis and clostridia in newborn piglets and its prevention by early treatment with toltrazuril

Abstract

In this study, 51 piglets originating from five different sows were included in the investigations. The animal source of all sows had a history of Clostridium perfringens type A (β2) infection. The piglets of three sows (n = 31) were experimentally infected with Isospora suis within the first 4 h after birth and were randomly assigned to the treatment group or the sham-dosing group. The piglets of the two remaining sows (n = 20) served as I. suis-uninfected controls. Twelve hours post-infection, the animals in the treatment group (n = 15) were treated with toltrazuril (20 mg/kg BW, Baycox® 5% suspension). During an observation period of 14 days faecal consistency, faecal oocyst counts, faecal germ counts, mortality, body weight development and clinical status were recorded. One piglet per study group and litter was necropsied, and intestinal tissue samples were taken for histopathological investigations and in situ hybridisation on study days (SDs) 3 and 14. I. suis-infected but untreated piglets showed clinical disease resulting in liquefaction of faeces and decreased body weight development. In 59.2% of the observations, I. suis-infected but untreated piglets showed abnormal faecal consistencies whereas only 12.0% or respectively 4.4% of the faecal samples had a pasty consistency in the I. suis-infected-treated or in the control animals. The mean body weight at the end of the study was 3.37 kg in the I. suis-infected but untreated piglets while the average body weight in the I. suis-infected-treated animals was calculated as 4.42 kg and the control animal's mean body weight was 4.45 kg. Moreover, mortality, occurring between SDs 8 and 14, in this study group was 38.5% (n = 5), with 30.8% (n = 4) died from necrotic enteritis. In contrast, no piglets died in the I. suis-uninfected control group or in the toltrazuril-treated study group. The results of this study corroborate the hypothesis that simultaneous infection with I. suis and C. perfringens type A soon after birth leads to distinct interactions between the two pathogens and result in an increase in clinical disease, mortality and metabolically active C. perfringens type A.

Efficacy of early treatment with toltrazuril in prevention of coccidiosis and necrotic enteritis in chickens

“…In the present study no Eimeria oocysts were detected after early treatment with toltrazuril before or up to 36 h after Eimeria infection, respectively. Similar results were achieved by Mengel et al (2012), who applied a single dose of toltrazuril and completely suppressed oocyst excretion and diarrhoea in piglets co-infected with I. suis and C. perfringens. Mengel et al (2012) also concluded that toltrazuril prevents a severe coccidial multiplication and thus increased mucus production, which would promote a secondary clostridial infection and clinical disease.…”

“…Arrows, necrotic foci; arrowheads, cell detritus and exudate above destroyed mucosa. laboratory, early treatment with toltrazuril prevented NE resulting from simultaneous infection with Isospora suis and C. perfringens in newborn piglets (Mengel et al, 2012).…”

Isospora suis in an Epithelial Cell Culture System – An In Vitro Model for Sexual Development in Coccidia

“…This system provided complete development to oocysts but no sporulation [15]. Beside these findings in vivo infection models for neonatal porcine coccidiosis are well described [16,17] and successfully used for drug efficacy testing [18,19], investigations of the immune response [20–22], and for co-infection modeling [23]. Therefore, a reproducible in vitro system including sexual stages and sporulated oocysts together with the knowledge obtained during in vivo trials could deliver an integral approach to the understanding of neonatal porcine coccidiosis and coccidian development as well as host-parasite interactions in these parasites.…”

Increase of Clostridium perfringens in association with Eimeria in haemorrhagic enteritis in Japanese beef cattle

“…Based on data obtained in this study, E. zuernii is likely to play a crucial role in massive multiplication of C. perfringens under certain conditions, such as stress in response to transportation or vitamin A deficiency, which underpins the pathophysiology demonstrated in pigs (Mengel and others 2012) and chickens (Collier and others 2008). Both E. zuernii and clostridia are widely distributed in cattle farms, and thus, severe E. zuernii infection and subsequent overgrowth of C. perfringen s in the intestine appear to be a likely event in conventional herds.…”