Lipopolysaccharides from *Salmonella enterica* serotype Abortusequi are endotoxins and TLR-4 activators derived from intestinal S. enterica. They are mutated R-type LPSs that serve as pathogen-associated molecular patterns (PAMP) to activate the immune system and induce cell secretion of exosomes. These lipopolysaccharides consist of a core oligosaccharide and lipid A. *S. enterica* serotype Abortusequi is a key pathogen causing abortion in mares and is associated with neonatal septicemia, multiple abscesses, orchitis, and polyarthritis in equine species. Grouping is primarily based on lipopolysaccharide (O-antigen) and flagellin protein (H-antigen).