Emerging toxins and emerging concerns: determination of selected mycotoxins in rabbit and rodent pet food using liquid chromatography-tandem mass spectrometry

Emerging mycotoxins are defined as fungal metabolites not yet regulated or routinely monitored—are gaining attention due to their potential health impacts and widespread occurrence in food and feed. These emerging mycotoxins are known to exert diverse in vitro toxic effects. Furthermore, they share relevant antimicrobial properties, which may affect intestinal microbiota and hence gut health, immunity and animal welfare, particularly in herbivorous species. Despite growing interest in small herbivorous pets such as rabbits and rodents, limited data are available on mycotoxin contamination in their commercial diets. This study aimed to develop and validate a reliable LC–MS/MS method for the simultaneous determination of selected emerging mycotoxins—such as beauvericin (BEAU), enniatins (ENN A, A1, B, B1), and alternariol (AOH)—in rabbit and rodent feed. A total of 200 feed samples (100 each for rabbit and rodent feed) were randomly collected from pet shops and markets in Bangkok, Thailand. Sample preparation was based on the QuEChERS approach, and detection was performed using liquid chromatography–tandem mass spectrometry with electrospray ionization in multiple reaction monitoring mode. Method validation was conducted according to SANTE/11,312/2021 guidelines, demonstrating acceptable performance in terms of selectivity, linearity, recovery, precision, and LOQ. The results revealed contamination with at least one emerging mycotoxin in 50% of rabbit feed and 39% of rodent feed samples, with BEAU being the most frequently detected compound. Co-contamination of BEAU and ENNs was found in 13.2% of rabbit feed and 8.2% of rodent feed samples, while AOH was not detected. These findings highlight the need for routine monitoring of emerging mycotoxins in pet food, especially for herbivorous small pets that may be rather vulnerable to microbiota-disrupting agents. The validated method offers a practical tool for quality assurance in the pet food sector and feed and food safety surveillance in general.