Microbiological pathogens in fecal samples of foals during the first year of life

Abstract

Objective The objective of the study was to investigate the age dependent occurrence of different infectious agents in foals with diarrhea.

Material and Methods Fecal samples, which were submitted to a commercial laboratory for a PCR-profile “Foal Diarrhea Pathogens” from 01.01.2021 up to 31.12.2022 (n=144), were examined for Equine Coronavirus (ECoV), Lawsonia (L.) intracellularis, Rhodococcus (R.) hoagii (=R. equi), Clostridium (Cl.) perfringens toxin-encoding genes cpa, cpe, cpb, etx and netF, Clostridioides (C.) difficile toxin-encoding genes tcdA and tcdB, as well as Rotavirus A via PCR.

Results Pathogens could be detected in a high proportion (42.9%) of the samples. Rotavirus A was the most prevalent pathogen in the current study, followed by clostridial species. Especially in foals younger than one month, netF-producing Cl. perfringens was detected frequently. In this age group, netF-producing Cl. perfringens was as prevalent as Rotavirus A. In comparison, R. hoagii, L. intracellularis and ECoV were detected rarely. Cl. perfringens toxin-encoding genes cpb and etx were not present in the examined samples. In general, the previously known age dependency of the investigated pathogens could be confirmed. Nevertheless, Rotavirus A and netF-positive Cl. perfringens could also be detected outside of the most susceptible age group. Coinfections with the examined pathogens had a low prevalence in the current study.

Conclusions In general, the examined pathogens showed an age dependent occurrence, but infections in foals outside of the common age group could not be ruled out with certainty due to small sample numbers in some of the age groups. Although Rotavirus A was the most prevalent pathogen in this study, netF-producing Cl. perfringens is an important differential diagnosis, especially in newborn foals. The diagnostic approach in diarrheic foals should contain a broad spectrum of pathogens. This is not only important to detect coinfections, but also to detect shedders, in order to protect other horses in the stable.

Zusammenfassung

Ziel Das Studienziel war die Ermittlung der Nachweishäufigkeit verschiedener Infektionserreger bei durchfallerkrankten Fohlen unter Berücksichtigung des Alters.

Material und Methoden 144 Kotproben, die vom 01.01.2021 bis 31.12.2022 für das Profil „Durchfallerreger Fohlen“ in ein kommerzielles Labor eingeschickt wurden, wurden mittels PCR auf folgende Infektionserreger untersucht: Equines Coronavirus (ECoV), Lawsonia (L.) intracellularis, Rhodococcus (R.) hoagii (=R. equi), Clostridium (Cl.) perfringens toxinbildenden Gene cpa, cpe, cpb, etx und netF, Clostridioides (C.) difficile toxinbildenden Gene tcdA und tcdB sowie Rotavirus A.

Ergebnisse In einem großen Anteil der Proben (42,9%) war mindestens einer der untersuchten Erreger nachweisbar. Rotavirus A wurde hierbei, gefolgt von Clostridien, am häufigsten detektiert. Vor allem bei Fohlen im ersten Lebensmonat waren netF-bildende Cl. perfringens häufig nachweisbar. In dieser Altersgruppe war die Nachweishäufigkeit von netF-positiven Cl. perfringens und Rotavirus A sogar identisch. Im Vergleich dazu spielten R. hoagii, L. intracellularis und ECoV eine untergeordnete Rolle. Die Cl. perfringens toxinbildenden Gene cpb und etx wurden nicht nachgewiesen. Im Allgemeinen konnte das altersabhängige Auftreten der untersuchten Pathogene bestätigt werden. Allerdings gelang bei Rotavirus A und netF-bildenden Cl. perfringens auch ein Nachweis außerhalb der als besonders empfänglich geltenden Altersgruppen. Koinfektionen mit den untersuchten Infektionserregern traten in der vorliegenden Studie selten auf.

Schlussfolgerung Generell zeigten die untersuchten Erreger ein altersabhängiges Auftreten. Infektionen bei Fohlen außerhalb der üblichen Altersgruppe können jedoch aufgrund kleiner Probenzahlen in einigen der Altersgruppen nicht mit Sicherheit ausgeschlossen werden. Auch wenn Rotaviren am häufigsten nachgewiesen werden konnten, stellen netF-bildende Cl. perfringens, vor allem bei neugeborenen Fohlen, eine wichtige Differentialdiagnose dar. Die diagnostische Aufarbeitung von Fohlendurchfall sollte ein breites Spektrum an Infektionserregern abdecken. Dieses Vorgehen ermöglicht nicht nur eine erfolgreiche Therapie erkrankter Tiere, sondern auch einen effektiven Schutz anderer Pferde im Bestand.

Keywords

Foal diarrhea - Clostridial toxins - Rotavirus A - Equine Coronavirus - Lawsonia intracellularis - Rhodococcus hoagii

Schlüsselwörter

Fohlendurchfall - Clostridientoxine - Rotavirus A - Equines Coronavirus - Lawsonia intracellularis - Rhodococcus hoagii

Publication History

Received: 16 April 2024

Accepted: 22 October 2024

Article published online:
05 December 2024

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