Publikationsdatenbank

Listeria infection in the glandular gastric mucosa of an Icelandic horse after omeprazole and sucralfate treatment (2025)

Art

Zeitschriftenartikel / wissenschaftlicher Beitrag

Autoren

Wittenberg, Jana (WE 17)

Gehlen, H. (WE 17)

Stöckle, Sabita Diana (WE 17)

Quelle

Compendium Pferdeheilkunde

Bandzählung: 1

Heftzählung: 4

Seiten: 271 – 278

ISSN: 2943-1808

Sprache

Englisch

Verweise

DOI: 10.21836Compendium20250403

Kontakt

Pferdeklinik

Oertzenweg 19 b
14163 Berlin
+49 30 838 62299 / 62300
pferdeklinik@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Listeria monocytogenes infections in adult horses are infrequent and typically present as encephalitis, abortion, or septicemia.
Rare manifestations such as keratitis, kerato-conjunctivitis, and acute enteritis have also been described. While Listeria is well-documented in
ruminants, particularly those fed silage, infection of the equine glandular gastric mucosa has not previously been reported. An adult Icelandic
mare fed a silage-based diet was referred to the Equine Clinic in October 2023 for evaluation of recurrent episodes of colic. Gastroscopy
and follow-up revealed severe equine squamous gastric disease (ESGD grade 4/4) and moderate equine glandular gastric disease (EGGD).
Treatment was initiated with omeprazole (4 mg/kg PO q24h) and sucralfate (12 mg/kg PO q12h) for a total of 10 weeks. The mare showed
marked clinical improvement, and follow-up gastroscopy demonstrated complete healing of the squamous mucosa and a physiologic proximal
duodenum. However, multiple vesiculopustular lesions were observed across the glandular mucosa. At that time, the mare displayed no
systemic signs of infection; vital parameters and laboratory findings were within normal limits. Biopsies were taken from the glandular mucosa
lesions for histopathology and microbial culture. Histological examination revealed an inflammatory infiltrate predominantly composed of
eosinophils and lymphoplasmacytic cells, and Listeria monocytogenes was confirmed by microbial culture. Based on antimicrobial susceptibility
testing, treatment with sulfadimethoxine-trimethoprim (30 mg/kg PO q12h) was initiated and continued for two weeks, while reduced
gastric ulcer therapy (omeprazole (1 mg/kg PO q24h); sucralfate (12 mg/kg PO q12h)) was maintained. Follow-up endoscopy performed
three weeks after the mare’s last presentation and completion of antimicrobial therapy revealed complete resolution of the glandular lesions,
and bacterial culture of the gastric mucosa yielded no evidence of Listeria monocytogenes. This case represents the first documented instance
of glandular gastric Listeria infection in a horse and highlights the importance of considering atypical presentations of listeriosis, particularly
in horses receiving acid-suppressive therapy and fed silage. While microbial culture of gastric mucosa is not routinely performed in equine
gastric ulcer syndrome (EGUS), this case demonstrates its diagnostic and therapeutic value. The successful resolution of the infection with a
trimethoprim-sulfonamide combination underlines the importance of targeted antimicrobial therapy in managing unusual bacterial gastric
infections. Furthermore, it raises the possibility that acid suppression in combination with silage feeding may predispose to glandular Listeria
infection in horses, warranting consideration in similar clinical scenarios.